American Journal of Transplantation 2015; 15: 1400–1406 Wiley Periodicals Inc.
C
Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons doi: 10.1111/ajt.13108
Brief Communication
Coronary Microvascular Dysfunction Correlates With the New Onset of Cardiac Allograft Vasculopathy in Heart Transplant Patients With Normal Coronary Angiography F. Tona1,*, E. Osto2, G. Famoso1, M. Previato1, M. Fedrigo1, A. Vecchiati1, M. Perazzolo Marra1, S. Tellatin1, R. Bellu1, G. Tarantini1, G. Feltrin1, A. Angelini1, G. Thiene1, G. Gerosa1 and S. Iliceto1
prednisone in the first year; RS, rejection score; RS 1st yr, rejection score in first year; sev TRS, rejection score in the total follow up including only severe grades; sev TRS 1st yr, rejection score in the first year including only severe grades; TDE, transthoracic Doppler echocardiography; TOTCORT 1st yr, total steroid load in the first year; TRS, rejection score in the total follow up
1
Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy 2 Cardiology and Centre for Molecular Cardiology, University Hospital and University of Zurich, Zurich, Switzerland Corresponding author: Francesco Tona, [email protected]
Coronary microvascular dysfunction is emerging as a strong predictor of outcome in heart transplantation (HT). We assessed the validity of microvascular dysfunction, defined by means of a reduced coronary flow reserve (CFR), as a factor associated with new onset epicardial cardiac allograft vasculopathy (CAV) or death. We studied 105 patients at 4 1 years post-HT with a normal coronary angiography (CA). New onset CAV was assessed by CA. CFR was assessed in the left anterior descending (LAD) coronary artery by transthoracic Doppler echocardiography and calculated as the ratio of hyperaemic to basal blood flow velocity. A CFR 2.5 was considered abnormal. Epicardial CAV onset or death was assessed during a follow-up of 10 years. New onset CAV was diagnosed in 30 patients (28.6%) (Group A), and the CA was normal in the remaining 75 patients (71.4%) (Group B). Group A had reduced CFR compared with group B (2.4 0.6 vs. 3.2 0.7, p < 0.0001). A CFR 2.5 was independently associated with a higher probability of new onset CAV (p < 0.0001) and a higher probability of death, regardless of CAV onset (p < 0.01). Microvascular dysfunction is independently associated with the onset of epicardial CAV, and associated with a higher risk of death, regardless of CAV onset. Abbreviations: CA, coronary angiography; CAV, cardiac allograft vasculopathy; CFR, coronary flow reserve; HT, heart transplantation; IVUS, intravascular ultrasound; LAD, left anterior descending coronary artery; MethPD 1st yr, methylprednisolone in the first year; PDN 1st yr, 1400
Received 02 June 2014, revised and accepted for publication 09 November 2014
Introduction Although the long-term outcome has improved over the past few years, cardiac allograft vasculopathy (CAV) remains the major cause of mortality after heart transplantation (HT). In CAV, both the epicardial coronary vessels and the microvasculature may be affected (1). Early studies on CAV mainly investigated the epicardial disease, although recently the focus has shifted instead to the role of the coronary microcirculation (1–4). An early diagnosis of CAV is crucial to identify recipients prone to developing the disease and thus suffering subsequent allograft failure. There is a growing interest in the assessment of the microcirculatory function in the coronary vascular bed as this is the principal level where the control over myocardial tissue perfusion occurs (2–8). Therefore, the microvascular function assessment may be more physiologically relevant than the detection of alterations in the epicardial arteries. Recently, stenotic microvasculopathy (detected in biopsy samples) has been characterized as an independent prognostic factor for long-term survival after HT (3), although this characterization has sparked controversy (9). Coronary flow reserve (CFR) is an important functional parameter commonly used to investigate the pathophysiology of the coronary circulation. The ability to detect and distinguish changes in epicardial and microvascular function early and noninvasively may help identify modifiable factors that lead to CAV. Our group has previously shown that CFR assessed by transthoracic Doppler echocardiography (TDE) detects the presence of concomitant established CAV, defined using both angiographic and intravascular ultrasound (IVUS) criteria (5,6). Furthermore, CFR by TDE has
Microvascular Dysfunction Correlates With CAV
been demonstrated to be a reliable, noninvasive marker for CAV-related cardiac events (2). In this retrospective exploratory study, we aimed to determine whether microvascular dysfunction, defined as a reduced CFR by TDE, is a valid predictor of new onset epicardial CAV in a long-term follow-up after HT.
Methods Study patients Patients were included in the study if they received a primary HT before December 31, 2003 and survived at least one year. Pts who had at least one CFR performed by TDE evaluation (within 1–4 years after HT) simultaneously with the coronary angiography (CA) and without evidence of angiographic CAV were included in the study. Patients with severe renal impairment did not undergo CA. According to the protocol of our center, CA was performed every 2 years. Outcome data over the 10 years were retrieved from medical records. Sixty patients underwent a second CFR evaluation after 3 1 years from the first evaluation. Our immunosuppression protocol has been previously detailed (2). Patients treated with everolimus or mycophenolate mofetil since the time of transplantation were excluded from the study. The study was approved by the institutional ethics committee, and all patients gave their written informed consent.
Angiography/diagnosis of CAV Cardiac catheterization was performed within 24 h of CFR evaluation by TDE. The angiograms were reviewed by a cardiologist (G.T.) who was unaware of the clinical and echocardiographic findings. At first, the data were analyzed using a qualitative grading system, as previously described (2). Later, CAV was defined in accordance with the new ISHLT classification (10).
Coronary flow velocity reserve assessment The CFR evaluation by TDE was performed as previously described (2,5,6). Briefly, CFR was measured in the distal part of the left anterior descending artery (LAD) in a modified foreshortened two-chamber view, with Doppler recordings of the basal flow and during adenosine infusion at a rate of 0.14 mg/kg/min for 3 min (Figure 1). Cardiac medications were not interrupted before the adenosine administration, although all medications or methylxanthine-containing substances were suspended 48 h prior to the study. Beverages containing methylxanthine substances were restricted for 24 h before the study. CFR in the LAD was calculated as the ratio of hyperaemic to basal diastolic flow velocity (for each parameter, the highest of three cycles was averaged) by one experienced echocardiographer performing the test blinded to the angiographic and clinical data (Figure 1). To account for differences in cardiac work, resting diastolic coronary flow velocities were normalized to the corresponding rate-pressure product by dividing the resting blood flow velocity by the rate-pressure product (an index of cardiac work), multiplied by a linear factor of 10 000 in each individual patient. A CFR 2.5 was considered abnormal (11).
Figure 1: Foreshortened two-chamber view with the display of coronary flow in the LAD (arrows), with Doppler recordings of the basal flow (top) and during hyperemia with adenosine infusion (bottom). D, diastolic; S, systolic.
Cumulative immunosuppressive doses The cumulative doses (milligrams per kilogram) of cyclosporine, azathioprine, prednisone and methylprednisolone at 3, 6 and 12 months and the cumulative total steroid load in the first year were calculated. The cumulative prednisone load for each patient in the first year (prednisone in the first year [PDN 1st yr]) was calculated (in milligrams per kilogram), as was the cumulative methylprednisolone in the first year (MethPD 1st yr) and total steroid load in the first year (TOTCORT 1st yr ¼ PDN 1st yr þ MethPD 1st yr) following the conversion of each methylprednisolone dose to an equivalent prednisone dose (4 mg of methylprednisolone ¼ 5 mg of prednisone) (12). Some patients have subsequently changed therapy and used other drugs such as tacrolimus (2.9%), mycophenolate mofetil (30.5%) and everolimus (16.2%).
Statistical analysis Acute rejection scores (RSs) Acute graft rejection was monitored by endomyocardial biopsy utilizing established protocols (2). An RS was assigned based on a modification of the ISHLT grading as detailed (12). The following scores were calculated for each patient: RS in the total follow up (TRS), RS in the first year (RS 1st yr), RS including only severe grades (3A) (sev TRS) and the first-year RS including only severe grades (sev TRS 1st yr). All scores were normalized for the number of biopsies taken in each patient.
American Journal of Transplantation 2015; 15: 1400–1406
Continuous variables with no/mild skew were presented as the mean SD; skewed measures such as medians were represented with the first and third quartiles (Q1–Q3). Discrete variables were summarized as frequencies and percentages. The distribution of the data was analyzed with a 1-sample Kolmogorov–Smirnov test. Continuous data were compared using the 2-tailed paired or unpaired t test (for normally distributed datasets) or the Mann–Whitney U or Wilcoxon signed-rank test (for skewed variables). Categorical variables were compared using the x2 test or Fisher’s exact test
1401
Tona et al as appropriate. Comparisons among the four ISHLT CAV grades were performed using 1-way ANOVA followed by multiple comparisons with the Tukey’s post hoc test for continuous variables. Bivariate correlations were assessed by the Pearson coefficient (r). Linear regression analysis was used to determine the factors independently associated with the change in CFR from baseline. The CAV-free survival and cumulative survival curves were traced by the Kaplan–Meier method and compared with the log-rank test. Unadjusted and multiple Cox regression analyses were performed with a combination of forward and backward selection procedures to aid in determining the best model of factors independently associated with epicardial CAV onset and cardiac death. The summary statistics for the Cox regression models included the C statistic and x2 of the models. Intraobserver and interobserver reproducibility of CFR was evaluated by linear regression analysis and expressed as the correlation of coefficients (r) and standard error of estimates (SEE) and by the intraclass correlation coefficient (ICC). Reproducibility is considered satisfactory if the intraclass correlation coefficient is between 0.81 and 1.0. Intraobserver and interobserver reproducibility measurements were calculated in all patients. All tests were 2 sided, and there was statistical significance if the null hypothesis could be rejected at p < 0.05. The data were analyzed with SPSS software version 20.0 (SPSS, Inc., Chicago, IL).
Results Baseline clinical and diagnostic features A total of 105 primary HT patients transplanted before December 31, 2003 who had survived at least one year, had CFR evaluations performed and had normal coronary angiograms were reviewed. In the follow-up, new onset epicardial CAV was diagnosed in 30 patients (28.6%) (Group A), whereas the CA remained normal in 75 patients (71.4%) (Group B). The baseline characteristics of the recipients and donors are shown in Table 1. No difference between patients that changed immunosuppressive protocol, introducing everolimus or mycophenolate mofetil, and the others, were detected. There were no regional wall motion abnormalities detected by echocardiography. Coronary flow reserve evaluation TDE studies have always been well tolerated. There were no significant electrocardiographic changes or left ventricular wall motion abnormalities during the adenosine infusion in any of our patients. In the whole patients group, the CFR was 3.05 0.7. The CFR was 2.5 in 24 (23%) patients. The diastolic peak velocity during adenosine and CFR was lower in group A (68 21 vs. 81 19 cm/s, p ¼ 0.01 and 2.6 0.8 vs. 3.2 0.7, p < 0.0001, respectively) (Table 2). The CFR was correlated with the ISHLT CAV grade (p < 0.001 for all comparisons) (Figure 2). CFR 2.5 was more frequent in group A (15 [48%] vs. 9 [12%], p < 0.0001). The intraobserver reproducibility of CFR was high (r ¼ 0.93, SEE ¼ 0.11); ICC was 0.972. The interobserver reproducibility of CFR was also high (r ¼ 0.90, SEE ¼ 0.10); ICC was 0.963. 1402
Table 1: Baseline patient characteristics (n ¼ 105) Group A (n ¼ 30) Age at HT, years 54 10 Male gender, n (%) 23 (74) BMI 25 2 IHD before HT, n (%) 10 (35) Hypertension, n (%) 14 (46) Diabetes, n (%) 5 (17) Cholesterol (mmol/L) 5 0.8 Triglycerides (mmol/L) 2 0.5 Echocardiographic characteristics 50 4 LVIDd (mm) LV mass/height2.7 (g/m2.7) 47 13 LVEF (%) 66 9 E/A 1.7 0.4 13 1.4 E/E0 Septal Donor characteristics Donor age (years) 34 11 Male donor gender, n (%) 22 (73) Gender mismatch, n (%) 3 (10) Ischaemic time (min) 170 35 Immunosuppression and rejection scores Triple therapy, n (%) 15 (50) TRS 1.16 0.5 1.21 0.5 RS 1st year Sev TRS 0.42 0.04 Sev RS 1st year 0.46 0.04 CsA at 12 months (mg/kg) 2218 308 Aza at 12 months (mg/kg) 521 109 PDN at 12 months (mg/kg) 50 10 MethPD 1st year (mg/kg) 67 23 168 76 TOTCORT1st year (mg/kg)
Group B (n ¼ 75)
p
51 12 55 (74) 26 2 25 (33) 43 (57) 6 (8) 5.3 1 1.6 0.5
0.1 1 0.8 0.8 0.2 0.2 0.3 0.05
51 8 49 7 69 7 1.5 0.3 10 2
0.6 0.4 0.2 0.2 0.1
35 9 50 (66) 5 (7) 160 28
0.7 0.2 0.2 0.3
20 (27) 1.1 0.5 1.15 0.6 0.38 0.04 0.44 0.05 1953 465 515 100 34 11 54 18 111 76
0.03 0.5 0.6 0.7 0.8 0.3 0.9 0.2 0.5 0.03
A wave indicates flow velocity during atrial contraction; Aza, azathioprine; BMI, body mass index; CsA, cyclosporin A; E wave, early transmitral diastolic flow velocity; E/E0 , ratio of early transmitral diastolic flow velocity (E) and early diastolic velocity recorded by Doppler tissue imaging (E0 ) in the mitral annulus; IHD, ischaemic heart disease; LV, left ventricular; LVEF, LV ejection fraction; LVIDd, LV internal diameter in diastole; MethPD, methylprednisolone; PDN, prednisone; RS 1st year, rejection score in the 1st year; Sev RS 1st year, rejection score in the 1st year including only severe grades (3A); sev TRS, rejection score in the total follow-up including only severe grades (3A); TOTCORT, total steroid load and TRS, rejection score in the total follow-up. Unless specified otherwise, the values are means SD.
Predictors of epicardial CAV-free survival The patients were followed for up to 10 years for the outcome analysis. Thirty (28.6%) angiograms were classified as new onset CAV, with 19 (63%) classified as CAV grade 1, 4 (13%) as CAV grade 2 and 7 (24%) as CAV grade 3. Only three patients underwent coronary artery stenting. Figure 3 illustrates the Kaplan– Meier epicardial CAV-free survival curve associated with CFR 2.5 (p < 0.001). The unadjusted predictors of new onset epicardial CAV are summarized in Table 3. Factors independently associated with epicardial CAV onset are summarized in Table 3. Independent factors American Journal of Transplantation 2015; 15: 1400–1406
Microvascular Dysfunction Correlates With CAV Table 2: Hemodynamic parameters during CFR evaluation (n ¼ 105) Group A (n ¼ 30)
Group B (n ¼ 75)
p
85 11 90 13 142 23 127 24 86 10 77 14 105 13 94 17 12 043 2321 27 9 23 7 68 21 2.6 0.8 2.7 0.6
88 12 94 17 136 18 123 20 85 15 77 14 102 14 92 15 12 010 2283 25 6 22 7 81 19 3.2 0.7 3.4 0.7
0.2 0.2 0.2 0.4 0.5 0.9 0.3 0.6 0.9 0.2 0.4 0.01
C
Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons doi: 10.1111/ajt.13108
Brief Communication
Coronary Microvascular Dysfunction Correlates With the New Onset of Cardiac Allograft Vasculopathy in Heart Transplant Patients With Normal Coronary Angiography F. Tona1,*, E. Osto2, G. Famoso1, M. Previato1, M. Fedrigo1, A. Vecchiati1, M. Perazzolo Marra1, S. Tellatin1, R. Bellu1, G. Tarantini1, G. Feltrin1, A. Angelini1, G. Thiene1, G. Gerosa1 and S. Iliceto1
prednisone in the first year; RS, rejection score; RS 1st yr, rejection score in first year; sev TRS, rejection score in the total follow up including only severe grades; sev TRS 1st yr, rejection score in the first year including only severe grades; TDE, transthoracic Doppler echocardiography; TOTCORT 1st yr, total steroid load in the first year; TRS, rejection score in the total follow up
1
Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy 2 Cardiology and Centre for Molecular Cardiology, University Hospital and University of Zurich, Zurich, Switzerland Corresponding author: Francesco Tona, [email protected]
Coronary microvascular dysfunction is emerging as a strong predictor of outcome in heart transplantation (HT). We assessed the validity of microvascular dysfunction, defined by means of a reduced coronary flow reserve (CFR), as a factor associated with new onset epicardial cardiac allograft vasculopathy (CAV) or death. We studied 105 patients at 4 1 years post-HT with a normal coronary angiography (CA). New onset CAV was assessed by CA. CFR was assessed in the left anterior descending (LAD) coronary artery by transthoracic Doppler echocardiography and calculated as the ratio of hyperaemic to basal blood flow velocity. A CFR 2.5 was considered abnormal. Epicardial CAV onset or death was assessed during a follow-up of 10 years. New onset CAV was diagnosed in 30 patients (28.6%) (Group A), and the CA was normal in the remaining 75 patients (71.4%) (Group B). Group A had reduced CFR compared with group B (2.4 0.6 vs. 3.2 0.7, p < 0.0001). A CFR 2.5 was independently associated with a higher probability of new onset CAV (p < 0.0001) and a higher probability of death, regardless of CAV onset (p < 0.01). Microvascular dysfunction is independently associated with the onset of epicardial CAV, and associated with a higher risk of death, regardless of CAV onset. Abbreviations: CA, coronary angiography; CAV, cardiac allograft vasculopathy; CFR, coronary flow reserve; HT, heart transplantation; IVUS, intravascular ultrasound; LAD, left anterior descending coronary artery; MethPD 1st yr, methylprednisolone in the first year; PDN 1st yr, 1400
Received 02 June 2014, revised and accepted for publication 09 November 2014
Introduction Although the long-term outcome has improved over the past few years, cardiac allograft vasculopathy (CAV) remains the major cause of mortality after heart transplantation (HT). In CAV, both the epicardial coronary vessels and the microvasculature may be affected (1). Early studies on CAV mainly investigated the epicardial disease, although recently the focus has shifted instead to the role of the coronary microcirculation (1–4). An early diagnosis of CAV is crucial to identify recipients prone to developing the disease and thus suffering subsequent allograft failure. There is a growing interest in the assessment of the microcirculatory function in the coronary vascular bed as this is the principal level where the control over myocardial tissue perfusion occurs (2–8). Therefore, the microvascular function assessment may be more physiologically relevant than the detection of alterations in the epicardial arteries. Recently, stenotic microvasculopathy (detected in biopsy samples) has been characterized as an independent prognostic factor for long-term survival after HT (3), although this characterization has sparked controversy (9). Coronary flow reserve (CFR) is an important functional parameter commonly used to investigate the pathophysiology of the coronary circulation. The ability to detect and distinguish changes in epicardial and microvascular function early and noninvasively may help identify modifiable factors that lead to CAV. Our group has previously shown that CFR assessed by transthoracic Doppler echocardiography (TDE) detects the presence of concomitant established CAV, defined using both angiographic and intravascular ultrasound (IVUS) criteria (5,6). Furthermore, CFR by TDE has
Microvascular Dysfunction Correlates With CAV
been demonstrated to be a reliable, noninvasive marker for CAV-related cardiac events (2). In this retrospective exploratory study, we aimed to determine whether microvascular dysfunction, defined as a reduced CFR by TDE, is a valid predictor of new onset epicardial CAV in a long-term follow-up after HT.
Methods Study patients Patients were included in the study if they received a primary HT before December 31, 2003 and survived at least one year. Pts who had at least one CFR performed by TDE evaluation (within 1–4 years after HT) simultaneously with the coronary angiography (CA) and without evidence of angiographic CAV were included in the study. Patients with severe renal impairment did not undergo CA. According to the protocol of our center, CA was performed every 2 years. Outcome data over the 10 years were retrieved from medical records. Sixty patients underwent a second CFR evaluation after 3 1 years from the first evaluation. Our immunosuppression protocol has been previously detailed (2). Patients treated with everolimus or mycophenolate mofetil since the time of transplantation were excluded from the study. The study was approved by the institutional ethics committee, and all patients gave their written informed consent.
Angiography/diagnosis of CAV Cardiac catheterization was performed within 24 h of CFR evaluation by TDE. The angiograms were reviewed by a cardiologist (G.T.) who was unaware of the clinical and echocardiographic findings. At first, the data were analyzed using a qualitative grading system, as previously described (2). Later, CAV was defined in accordance with the new ISHLT classification (10).
Coronary flow velocity reserve assessment The CFR evaluation by TDE was performed as previously described (2,5,6). Briefly, CFR was measured in the distal part of the left anterior descending artery (LAD) in a modified foreshortened two-chamber view, with Doppler recordings of the basal flow and during adenosine infusion at a rate of 0.14 mg/kg/min for 3 min (Figure 1). Cardiac medications were not interrupted before the adenosine administration, although all medications or methylxanthine-containing substances were suspended 48 h prior to the study. Beverages containing methylxanthine substances were restricted for 24 h before the study. CFR in the LAD was calculated as the ratio of hyperaemic to basal diastolic flow velocity (for each parameter, the highest of three cycles was averaged) by one experienced echocardiographer performing the test blinded to the angiographic and clinical data (Figure 1). To account for differences in cardiac work, resting diastolic coronary flow velocities were normalized to the corresponding rate-pressure product by dividing the resting blood flow velocity by the rate-pressure product (an index of cardiac work), multiplied by a linear factor of 10 000 in each individual patient. A CFR 2.5 was considered abnormal (11).
Figure 1: Foreshortened two-chamber view with the display of coronary flow in the LAD (arrows), with Doppler recordings of the basal flow (top) and during hyperemia with adenosine infusion (bottom). D, diastolic; S, systolic.
Cumulative immunosuppressive doses The cumulative doses (milligrams per kilogram) of cyclosporine, azathioprine, prednisone and methylprednisolone at 3, 6 and 12 months and the cumulative total steroid load in the first year were calculated. The cumulative prednisone load for each patient in the first year (prednisone in the first year [PDN 1st yr]) was calculated (in milligrams per kilogram), as was the cumulative methylprednisolone in the first year (MethPD 1st yr) and total steroid load in the first year (TOTCORT 1st yr ¼ PDN 1st yr þ MethPD 1st yr) following the conversion of each methylprednisolone dose to an equivalent prednisone dose (4 mg of methylprednisolone ¼ 5 mg of prednisone) (12). Some patients have subsequently changed therapy and used other drugs such as tacrolimus (2.9%), mycophenolate mofetil (30.5%) and everolimus (16.2%).
Statistical analysis Acute rejection scores (RSs) Acute graft rejection was monitored by endomyocardial biopsy utilizing established protocols (2). An RS was assigned based on a modification of the ISHLT grading as detailed (12). The following scores were calculated for each patient: RS in the total follow up (TRS), RS in the first year (RS 1st yr), RS including only severe grades (3A) (sev TRS) and the first-year RS including only severe grades (sev TRS 1st yr). All scores were normalized for the number of biopsies taken in each patient.
American Journal of Transplantation 2015; 15: 1400–1406
Continuous variables with no/mild skew were presented as the mean SD; skewed measures such as medians were represented with the first and third quartiles (Q1–Q3). Discrete variables were summarized as frequencies and percentages. The distribution of the data was analyzed with a 1-sample Kolmogorov–Smirnov test. Continuous data were compared using the 2-tailed paired or unpaired t test (for normally distributed datasets) or the Mann–Whitney U or Wilcoxon signed-rank test (for skewed variables). Categorical variables were compared using the x2 test or Fisher’s exact test
1401
Tona et al as appropriate. Comparisons among the four ISHLT CAV grades were performed using 1-way ANOVA followed by multiple comparisons with the Tukey’s post hoc test for continuous variables. Bivariate correlations were assessed by the Pearson coefficient (r). Linear regression analysis was used to determine the factors independently associated with the change in CFR from baseline. The CAV-free survival and cumulative survival curves were traced by the Kaplan–Meier method and compared with the log-rank test. Unadjusted and multiple Cox regression analyses were performed with a combination of forward and backward selection procedures to aid in determining the best model of factors independently associated with epicardial CAV onset and cardiac death. The summary statistics for the Cox regression models included the C statistic and x2 of the models. Intraobserver and interobserver reproducibility of CFR was evaluated by linear regression analysis and expressed as the correlation of coefficients (r) and standard error of estimates (SEE) and by the intraclass correlation coefficient (ICC). Reproducibility is considered satisfactory if the intraclass correlation coefficient is between 0.81 and 1.0. Intraobserver and interobserver reproducibility measurements were calculated in all patients. All tests were 2 sided, and there was statistical significance if the null hypothesis could be rejected at p < 0.05. The data were analyzed with SPSS software version 20.0 (SPSS, Inc., Chicago, IL).
Results Baseline clinical and diagnostic features A total of 105 primary HT patients transplanted before December 31, 2003 who had survived at least one year, had CFR evaluations performed and had normal coronary angiograms were reviewed. In the follow-up, new onset epicardial CAV was diagnosed in 30 patients (28.6%) (Group A), whereas the CA remained normal in 75 patients (71.4%) (Group B). The baseline characteristics of the recipients and donors are shown in Table 1. No difference between patients that changed immunosuppressive protocol, introducing everolimus or mycophenolate mofetil, and the others, were detected. There were no regional wall motion abnormalities detected by echocardiography. Coronary flow reserve evaluation TDE studies have always been well tolerated. There were no significant electrocardiographic changes or left ventricular wall motion abnormalities during the adenosine infusion in any of our patients. In the whole patients group, the CFR was 3.05 0.7. The CFR was 2.5 in 24 (23%) patients. The diastolic peak velocity during adenosine and CFR was lower in group A (68 21 vs. 81 19 cm/s, p ¼ 0.01 and 2.6 0.8 vs. 3.2 0.7, p < 0.0001, respectively) (Table 2). The CFR was correlated with the ISHLT CAV grade (p < 0.001 for all comparisons) (Figure 2). CFR 2.5 was more frequent in group A (15 [48%] vs. 9 [12%], p < 0.0001). The intraobserver reproducibility of CFR was high (r ¼ 0.93, SEE ¼ 0.11); ICC was 0.972. The interobserver reproducibility of CFR was also high (r ¼ 0.90, SEE ¼ 0.10); ICC was 0.963. 1402
Table 1: Baseline patient characteristics (n ¼ 105) Group A (n ¼ 30) Age at HT, years 54 10 Male gender, n (%) 23 (74) BMI 25 2 IHD before HT, n (%) 10 (35) Hypertension, n (%) 14 (46) Diabetes, n (%) 5 (17) Cholesterol (mmol/L) 5 0.8 Triglycerides (mmol/L) 2 0.5 Echocardiographic characteristics 50 4 LVIDd (mm) LV mass/height2.7 (g/m2.7) 47 13 LVEF (%) 66 9 E/A 1.7 0.4 13 1.4 E/E0 Septal Donor characteristics Donor age (years) 34 11 Male donor gender, n (%) 22 (73) Gender mismatch, n (%) 3 (10) Ischaemic time (min) 170 35 Immunosuppression and rejection scores Triple therapy, n (%) 15 (50) TRS 1.16 0.5 1.21 0.5 RS 1st year Sev TRS 0.42 0.04 Sev RS 1st year 0.46 0.04 CsA at 12 months (mg/kg) 2218 308 Aza at 12 months (mg/kg) 521 109 PDN at 12 months (mg/kg) 50 10 MethPD 1st year (mg/kg) 67 23 168 76 TOTCORT1st year (mg/kg)
Group B (n ¼ 75)
p
51 12 55 (74) 26 2 25 (33) 43 (57) 6 (8) 5.3 1 1.6 0.5
0.1 1 0.8 0.8 0.2 0.2 0.3 0.05
51 8 49 7 69 7 1.5 0.3 10 2
0.6 0.4 0.2 0.2 0.1
35 9 50 (66) 5 (7) 160 28
0.7 0.2 0.2 0.3
20 (27) 1.1 0.5 1.15 0.6 0.38 0.04 0.44 0.05 1953 465 515 100 34 11 54 18 111 76
0.03 0.5 0.6 0.7 0.8 0.3 0.9 0.2 0.5 0.03
A wave indicates flow velocity during atrial contraction; Aza, azathioprine; BMI, body mass index; CsA, cyclosporin A; E wave, early transmitral diastolic flow velocity; E/E0 , ratio of early transmitral diastolic flow velocity (E) and early diastolic velocity recorded by Doppler tissue imaging (E0 ) in the mitral annulus; IHD, ischaemic heart disease; LV, left ventricular; LVEF, LV ejection fraction; LVIDd, LV internal diameter in diastole; MethPD, methylprednisolone; PDN, prednisone; RS 1st year, rejection score in the 1st year; Sev RS 1st year, rejection score in the 1st year including only severe grades (3A); sev TRS, rejection score in the total follow-up including only severe grades (3A); TOTCORT, total steroid load and TRS, rejection score in the total follow-up. Unless specified otherwise, the values are means SD.
Predictors of epicardial CAV-free survival The patients were followed for up to 10 years for the outcome analysis. Thirty (28.6%) angiograms were classified as new onset CAV, with 19 (63%) classified as CAV grade 1, 4 (13%) as CAV grade 2 and 7 (24%) as CAV grade 3. Only three patients underwent coronary artery stenting. Figure 3 illustrates the Kaplan– Meier epicardial CAV-free survival curve associated with CFR 2.5 (p < 0.001). The unadjusted predictors of new onset epicardial CAV are summarized in Table 3. Factors independently associated with epicardial CAV onset are summarized in Table 3. Independent factors American Journal of Transplantation 2015; 15: 1400–1406
Microvascular Dysfunction Correlates With CAV Table 2: Hemodynamic parameters during CFR evaluation (n ¼ 105) Group A (n ¼ 30)
Group B (n ¼ 75)
p
85 11 90 13 142 23 127 24 86 10 77 14 105 13 94 17 12 043 2321 27 9 23 7 68 21 2.6 0.8 2.7 0.6
88 12 94 17 136 18 123 20 85 15 77 14 102 14 92 15 12 010 2283 25 6 22 7 81 19 3.2 0.7 3.4 0.7
0.2 0.2 0.2 0.4 0.5 0.9 0.3 0.6 0.9 0.2 0.4 0.01
