Review
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Update on percutaneous intervention for left main coronary artery stenosis Expert Rev. Cardiovasc. Ther. Early online, 1–11 (2015)
Pil Hyung Lee, Jung-Min Ahn and Seung-Jung Park* Division of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea *Author for correspondence: Tel.: +82 2 3010 4812 Fax: +82 2 486 5918 [email protected]
Percutaneous coronary intervention (PCI) using drug-eluting stents (DES) is currently considered as a viable alternative to coronary artery bypass graft surgery (CABG) for selected patients with left main coronary artery disease. The updated results of the landmark randomized trials comparing CABG versus PCI demonstrated comparable 5-year outcomes and are in line with the current guidelines that designate PCI as a reasonable treatment in this disease subset. Given that the completed randomized trials did not include contemporary DESs, the upcoming results of the ongoing trials evaluating the performance of newgeneration DES compared with CABG (such as the EXCEL trial), may further help to clarify the current role and future recommendations of PCI for left main coronary artery disease. Apart from the recent stent technology, further improvements in outcomes after PCI may be possible when it is used with an integrated approach that combines functional concepts for decision-making, adjunctive imaging support and optimal pharmacotherapies. KEYWORDS: bifurcation . drug-eluting stent . fractional flow reserve . intravascular ultrasound artery . outcomes
.
Owing to the long-term survival benefits of coronary artery bypass graft surgery (CABG) compared with medical therapy, CABG has been the standard of care for treatment of unprotected left main coronary artery (LMCA) disease since the 1970s [1–3]. However, the clinical applications of percutaneous coronary intervention (PCI) have been extended due to rapid advancements in techniques, devices, and adjunctive pharmacotherapies; this has enabled interventional cardiologists to test the feasibility of LMCA stenting. Particularly, the widespread availability of drug-eluting stents (DESs) has improved outcomes and lowered the threshold required for performing PCI instead of CABG for LMCA disease [4,5]. Several randomized controlled trials and large registries demonstrate that LMCA stenting with DES yields comparable mortality and morbidity rates to CABG, making unprotected LMCA intervention a potential alternative treatment [6–9]. As a result, during the past decade, the worldwide prevalence of LMCA stenting has considerably increased. Now that the field of unprotected LMCA revascularization is no longer a no-go area for interventional cardiologists, every
informahealthcare.com
.
left main coronary
percutaneous coronary intervention
10.1586/14779072.2015.1065730
endeavor should be made to understand the theoretical, practical and fundamental aspects of the management of LMCA disease. In this review, we evaluated the updated outcome data, current concepts and technical issues involved in LMCA intervention based on published evidences. Updated status: outcomes following treatments using PCI with DES versus CABG
Currently, several observational studies and randomized trials comparing the safety and efficacy of PCI using DES with CABG have been published [6–26]. One study that allows a comparison of the feasibility of PCI as an alternative to CABG used patients enrolled on the ‘Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty Versus Surgical Revascularization’ (MAIN-COMPARE) registry, which included 2240 patients with unprotected LMCA disease who underwent revascularization (bare-metal stent, n = 318; DES, n = 784; CABG, n = 1138) [6,10]. The 3-year outcome report using propensity-score
2015 Informa UK Ltd
ISSN 1477-9072
1
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Review
Lee, Ahn & Park
matching, and the 5-year report using the inverse probability of treatment weighting method, showed that the risk of death and the combined risk of death, Q-wave myocardial infarction (MI) or stroke, were not significantly different between patients undergoing PCI and those undergoing CABG. A similar pattern was observed in patients treated with either DES or bare-metal stent. However, the risk of repeat revascularization was significantly higher in the PCI group than in the CABG group: the DES recipients were almost six-fold more likely to require repeated revascularization compared with those who underwent surgery, while the bare-metal stent recipients were almost 10-fold more likely. Another large European all-comers multicenter registry, the ‘Drug-Eluting Stent for Left Main Coronary Artery Disease’ (DELTA) registry, which included 2775 patients with LMCA disease, who underwent PCI using DES (n = 1,874) and CABG (n = 901), also reported comparable outcomes between the two modalities [27]. After analysis of 602 propensity-matched pairs, there was no difference in the risk of the composite endpoint of death, MI or stroke (HR, 0.91; 95% CI, 0.66–1.26; p = 0.57) and mortality (HR, 1.00; 95% CI, 0.70–1.43; p = 1.00). However, there was still an advantage of CABG over PCI in terms of major adverse cardiac or cerebrovascular events (MACCE) which was driven by a significantly lower risk of target vessel revascularization (TVR; HR, 2.96; 95% CI, 1.84–4.74; p < 0.001) The ‘Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery’ (SYNTAX) trial compared the outcomes of PCI using paclitaxel-eluting stents versus CABG for unprotected LMCA stenosis in a subgroup analysis from a randomized study cohort [7]. In the subset of LMCA disease comprising 348 patients receiving CABG and 357 receiving PCI, PCI and CABG demonstrated equivalent 12-month rates of MACCE (PCI vs. CABG, 15.8 vs. 13.7%). In these patients, the higher rate of repeat revascularization after PCI (PCI vs. CABG, 11.8 vs. 6.5%; p = 0.01) was offset by a higher incidence of stroke after CABG (CABG vs. PCI, 2.7 vs. 0.3%; p = 0.01). Even after a 5-year follow-up period [28], there were no significant differences in the rates of death (PCI vs. CABG, 12.8 vs. 14.6%; p = 0.53), MI (PCI vs. CABG, 8.2 vs. 4.8%; p = 0.10) and MACCE (PCI vs. CABG, 36.9 vs. 31.0%; p = 0.12) between patients who received PCI and those who received CABG. The incidence of stroke was lower (PCI vs. CABG, 1.5 vs. 4.3%; p = 0.03), while the incidence of repeat revascularization was higher (PCI vs. CABG, 26.7 vs. 15.5%; p < 0.01) in the PCI group. When patients were stratified according to SYNTAX score terciles, the MACCE incidence rates did not differ between the PCI and CABG groups in patients with low (0–22) and intermediate (23–32) scores. Despite the information from the SYNTAX trial, it should be noted that the LMCA disease analysis was carried out as a post hoc analysis and was not the primary objective of the study; these results should therefore be considered as hypothesis generating. The ‘Premier of Randomized Comparison of Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary doi: 10.1586/14779072.2015.1065730
Artery Disease’ (PRECOMBAT) trial, a LMCA-targeted study, randomized 600 patients with unprotected LMCA disease to treatment with either CABG or PCI with sirolimus-eluting stent [8]. At 1 year, PCI was non-inferior to CABG for the incidence of MACCE (absolute risk difference, 2%; upper margin of 95% CI, 5.6%; HR, 1.56; p = 0.011 for non-inferiority). By 2 years, the MACCE rate (PCI vs. CABG, 12.2 vs. 8.1%; HR, 1.5; 95% CI, 0.9–2.52; p = 0.12) and the composite rate of death, MI or stroke (PCI vs. CABG, 4.4 vs. 4.7%; HR, 0.92; 95% CI, 0.43–1.96; p = 0.83) remained comparable between the PCI and CABG groups. However, the 2-year rate of ischemia-driven TVR was significantly higher in the PCI group than in the CABG group (9 vs. 4.2%; HR, 2.18; 95% CI, 1.1–4.32; p = 0.022). Recently, the final 5-year result of this trial has been demonstrated [26]. There was no betweengroup difference in the rates of MACCE (PCI vs. CABG, 17.5 vs. 14.3%; HR, 1.27; 95% CI, 0.84–1.90; p = 0.26), allcause death (5.7 vs. 7.9%, p = 0.32), MI (2.0 vs. 1.7%, p = 0.76), or stroke (0.7% in each group). However, the rate of ischemia-driven TVR remained significantly higher in the group that underwent PCI (11.4 vs. 5.5%; HR, 2.11; 95% CI, 1.16–3.84; p = 0.012). In summary, the cumulative evidences from these clinical trials indicate that PCI with DES yields comparable long-term outcomes to CABG. Although frequent repeat revascularization could be an inherent weakness of stent-related treatment, it is noteworthy that the observed increase in repeat revascularization after PCI using DES did not appear to translate into an increase in hard endpoints, such as death, myocardial infarction or stroke. Accordingly, the guidelines for the treatment of LMCA stenosis upgraded PCI as a reasonable or considerable treatment in prespecified patients (TABLE 1) [29,30]. Decision making in individual patients: PCI or CABG?
There are fundamental differences in the methodologies of PCI and CABG for treating coronary artery disease. In PCI, the lesion is directly relieved by stents, while in bypass surgery, a graft is placed on the mid-coronary vessel, beyond the lesion, where the epicardial vessel is relatively free of disease. Thus, one of the advantages of CABG over PCI is the achievement of more complete revascularizations, which leads to reductions in future revascularization rates. Although LMCA alone might be considered to be an attractive target for percutaneous intervention because of its large vessel size, short lesion length and lack of tortuosity, LMCA disease often coexists with multivessel disease (e.g., 72.7% in PRECOMBAT, 67.5% in SYNTAX left main subset), thus the choice of PCI or CABG for treatment of unprotected LMCA disease of each case should be based on the comprehensive clinical and anatomical features, and with consideration of the advantages and disadvantages of each procedure. Current standard approach to patients presenting with significant LMCA disease is to have them evaluated by both interventional cardiologists and cardiac surgeons and reach the decision to opt for PCI or surgery by consensus, on the basis of: hemodynamic status of the patient; lesion characteristics; vessel size; the presence of comorbidities; quality of arterial Expert Rev. Cardiovasc. Ther.
Review
Left main coronary artery stenosis
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Table 1. Current guidelines on PCI for significant unprotected left main coronary artery disease. Guidelines
Class of recommendation
LOE
2011 ACCF/AHA/SCAI Guideline
IIa—For SIHD patients when both of the following are present: . Anatomic conditions associated with a low risk of PCI procedural complications and a high likelihood of good long-term outcome (e.g., a low SYNTAX score [£22], ostial or trunk left main stenosis) . Clinical characteristics that predict a significantly increased risk of adverse surgical outcomes (e.g., STS-predicted risk of operative mortality ‡5%)
B
IIb—For SIHD patients when both of the following are present: . Anatomic conditions associated with a low to intermediate risk of PCI procedural complications and an intermediate to high likelihood of good long-term outcome (e.g., low-intermediate SYNTAX score of 2%)
B
III: HARM—For SIHD patients (versus performing CABG) with unfavorable anatomy for PCI and who are good candidates for CABG
B
I—Left main disease with a SYNTAX score £22
B
IIa—Left main disease with a SYNTAX score 23–32
B
III— Left main disease with a SYNTAX score >32
B
2014 ESC/EACTS Guideline
Ref. [29]
[30]
CABG: Coronary artery bypass graft; LOE: Level of evidence; PCI: Percutaneous coronary intervention; SIHD: Stable ischemic heart disease; STS: The Society of Thoracic Surgeons; SYNTAX: The Synergy between PCI with Taxus and Cardiac Surgery.
and/or venous conduits for grafting; and patient and/or referring physician preferences. Patients must always be fully informed about the potential risks and outcomes of both the surgical and the percutaneous approaches.
the catheterization laboratory. Particularly, because of the critical prognostic importance associated with functionally significant unprotected LMCA, the decision about whether to treat the intermediate LMCA stenosis should not be determined by the coronary angiogram alone.
Functional angioplasty for LMCA disease
For the past several decades, the decision to perform a coronary revascularization has been frequently based on the anatomic severity assessed by coronary angiogram alone. However, the conventional coronary angiogram is only a lumenogram and has critical limitations in assessing the actual functional severity. Furthermore, less than half of patients are noninvasively evaluated for myocardial ischemia before revascularization therapy in the real world practice [31], and the noninvasive functional tests, even when performed, does not provide lesion-specific information and are often inadequate to guide revascularization particularly in patients with complex coronary artery disease, such as LMCA or multivessel disease. One European study demonstrated a significant discordance (35% of all cases) between angiogram and fractional flow reserve (FFR) assessment of stenosis severity after analyzing more than 4000 coronary stenoses [32]. For the LMCA, Hamilos et al. [33] also discovered a considerable discrepancy between the two diagnostic modalities in the evaluation of intermediate stenosis where 29.1% of patients showed a ‘visual functional mismatch’ between angiographic and functional significance. In recent years, a definite paradigm shift has occurred in the treatment of coronary heart disease in that a growing burden of evidence advocates the concept of ‘functional coronary revascularization’ on a lesion level within informahealthcare.com
FFR for LMCA: making decision to treat or not to treat
Routine practice has already changed to include increased use of FFR for LMCA stenting [34,35]. FFR is a pressure-wire-based index used to identify ischemia-producing coronary stenosis and is simply expressed as the ratio between the mean pressure of the aorta and the mean pressure distal to the stenosis in the maximal coronary hyperemic condition. FFR is unique as it is not affected by hemodynamic conditions (e.g., blood pressure, heart rate or contractile state) and is lesion specific, which makes it ideally suited to the assessment of multiple lesions in patients with multivessel and left main disease. An FFR value of >0.75– 0.80, which means less than 20–25% reduction in maximal hyperemic blood flow due to stenotic lesion, has been suggested to be a strong predictor of favorable survival and low event rates in patients with intermediate LMCA disease, making it a useful cut-off value to determine significant LMCA stenosis. In a study involving 213 patients with intermediate LMCA stenosis, 5-year survival rates of 138 patients treated medically with an FFR ‡0.80, and 75 patients treated surgically with an FFR
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Update on percutaneous intervention for left main coronary artery stenosis Expert Rev. Cardiovasc. Ther. Early online, 1–11 (2015)
Pil Hyung Lee, Jung-Min Ahn and Seung-Jung Park* Division of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea *Author for correspondence: Tel.: +82 2 3010 4812 Fax: +82 2 486 5918 [email protected]
Percutaneous coronary intervention (PCI) using drug-eluting stents (DES) is currently considered as a viable alternative to coronary artery bypass graft surgery (CABG) for selected patients with left main coronary artery disease. The updated results of the landmark randomized trials comparing CABG versus PCI demonstrated comparable 5-year outcomes and are in line with the current guidelines that designate PCI as a reasonable treatment in this disease subset. Given that the completed randomized trials did not include contemporary DESs, the upcoming results of the ongoing trials evaluating the performance of newgeneration DES compared with CABG (such as the EXCEL trial), may further help to clarify the current role and future recommendations of PCI for left main coronary artery disease. Apart from the recent stent technology, further improvements in outcomes after PCI may be possible when it is used with an integrated approach that combines functional concepts for decision-making, adjunctive imaging support and optimal pharmacotherapies. KEYWORDS: bifurcation . drug-eluting stent . fractional flow reserve . intravascular ultrasound artery . outcomes
.
Owing to the long-term survival benefits of coronary artery bypass graft surgery (CABG) compared with medical therapy, CABG has been the standard of care for treatment of unprotected left main coronary artery (LMCA) disease since the 1970s [1–3]. However, the clinical applications of percutaneous coronary intervention (PCI) have been extended due to rapid advancements in techniques, devices, and adjunctive pharmacotherapies; this has enabled interventional cardiologists to test the feasibility of LMCA stenting. Particularly, the widespread availability of drug-eluting stents (DESs) has improved outcomes and lowered the threshold required for performing PCI instead of CABG for LMCA disease [4,5]. Several randomized controlled trials and large registries demonstrate that LMCA stenting with DES yields comparable mortality and morbidity rates to CABG, making unprotected LMCA intervention a potential alternative treatment [6–9]. As a result, during the past decade, the worldwide prevalence of LMCA stenting has considerably increased. Now that the field of unprotected LMCA revascularization is no longer a no-go area for interventional cardiologists, every
informahealthcare.com
.
left main coronary
percutaneous coronary intervention
10.1586/14779072.2015.1065730
endeavor should be made to understand the theoretical, practical and fundamental aspects of the management of LMCA disease. In this review, we evaluated the updated outcome data, current concepts and technical issues involved in LMCA intervention based on published evidences. Updated status: outcomes following treatments using PCI with DES versus CABG
Currently, several observational studies and randomized trials comparing the safety and efficacy of PCI using DES with CABG have been published [6–26]. One study that allows a comparison of the feasibility of PCI as an alternative to CABG used patients enrolled on the ‘Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty Versus Surgical Revascularization’ (MAIN-COMPARE) registry, which included 2240 patients with unprotected LMCA disease who underwent revascularization (bare-metal stent, n = 318; DES, n = 784; CABG, n = 1138) [6,10]. The 3-year outcome report using propensity-score
2015 Informa UK Ltd
ISSN 1477-9072
1
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Review
Lee, Ahn & Park
matching, and the 5-year report using the inverse probability of treatment weighting method, showed that the risk of death and the combined risk of death, Q-wave myocardial infarction (MI) or stroke, were not significantly different between patients undergoing PCI and those undergoing CABG. A similar pattern was observed in patients treated with either DES or bare-metal stent. However, the risk of repeat revascularization was significantly higher in the PCI group than in the CABG group: the DES recipients were almost six-fold more likely to require repeated revascularization compared with those who underwent surgery, while the bare-metal stent recipients were almost 10-fold more likely. Another large European all-comers multicenter registry, the ‘Drug-Eluting Stent for Left Main Coronary Artery Disease’ (DELTA) registry, which included 2775 patients with LMCA disease, who underwent PCI using DES (n = 1,874) and CABG (n = 901), also reported comparable outcomes between the two modalities [27]. After analysis of 602 propensity-matched pairs, there was no difference in the risk of the composite endpoint of death, MI or stroke (HR, 0.91; 95% CI, 0.66–1.26; p = 0.57) and mortality (HR, 1.00; 95% CI, 0.70–1.43; p = 1.00). However, there was still an advantage of CABG over PCI in terms of major adverse cardiac or cerebrovascular events (MACCE) which was driven by a significantly lower risk of target vessel revascularization (TVR; HR, 2.96; 95% CI, 1.84–4.74; p < 0.001) The ‘Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery’ (SYNTAX) trial compared the outcomes of PCI using paclitaxel-eluting stents versus CABG for unprotected LMCA stenosis in a subgroup analysis from a randomized study cohort [7]. In the subset of LMCA disease comprising 348 patients receiving CABG and 357 receiving PCI, PCI and CABG demonstrated equivalent 12-month rates of MACCE (PCI vs. CABG, 15.8 vs. 13.7%). In these patients, the higher rate of repeat revascularization after PCI (PCI vs. CABG, 11.8 vs. 6.5%; p = 0.01) was offset by a higher incidence of stroke after CABG (CABG vs. PCI, 2.7 vs. 0.3%; p = 0.01). Even after a 5-year follow-up period [28], there were no significant differences in the rates of death (PCI vs. CABG, 12.8 vs. 14.6%; p = 0.53), MI (PCI vs. CABG, 8.2 vs. 4.8%; p = 0.10) and MACCE (PCI vs. CABG, 36.9 vs. 31.0%; p = 0.12) between patients who received PCI and those who received CABG. The incidence of stroke was lower (PCI vs. CABG, 1.5 vs. 4.3%; p = 0.03), while the incidence of repeat revascularization was higher (PCI vs. CABG, 26.7 vs. 15.5%; p < 0.01) in the PCI group. When patients were stratified according to SYNTAX score terciles, the MACCE incidence rates did not differ between the PCI and CABG groups in patients with low (0–22) and intermediate (23–32) scores. Despite the information from the SYNTAX trial, it should be noted that the LMCA disease analysis was carried out as a post hoc analysis and was not the primary objective of the study; these results should therefore be considered as hypothesis generating. The ‘Premier of Randomized Comparison of Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary doi: 10.1586/14779072.2015.1065730
Artery Disease’ (PRECOMBAT) trial, a LMCA-targeted study, randomized 600 patients with unprotected LMCA disease to treatment with either CABG or PCI with sirolimus-eluting stent [8]. At 1 year, PCI was non-inferior to CABG for the incidence of MACCE (absolute risk difference, 2%; upper margin of 95% CI, 5.6%; HR, 1.56; p = 0.011 for non-inferiority). By 2 years, the MACCE rate (PCI vs. CABG, 12.2 vs. 8.1%; HR, 1.5; 95% CI, 0.9–2.52; p = 0.12) and the composite rate of death, MI or stroke (PCI vs. CABG, 4.4 vs. 4.7%; HR, 0.92; 95% CI, 0.43–1.96; p = 0.83) remained comparable between the PCI and CABG groups. However, the 2-year rate of ischemia-driven TVR was significantly higher in the PCI group than in the CABG group (9 vs. 4.2%; HR, 2.18; 95% CI, 1.1–4.32; p = 0.022). Recently, the final 5-year result of this trial has been demonstrated [26]. There was no betweengroup difference in the rates of MACCE (PCI vs. CABG, 17.5 vs. 14.3%; HR, 1.27; 95% CI, 0.84–1.90; p = 0.26), allcause death (5.7 vs. 7.9%, p = 0.32), MI (2.0 vs. 1.7%, p = 0.76), or stroke (0.7% in each group). However, the rate of ischemia-driven TVR remained significantly higher in the group that underwent PCI (11.4 vs. 5.5%; HR, 2.11; 95% CI, 1.16–3.84; p = 0.012). In summary, the cumulative evidences from these clinical trials indicate that PCI with DES yields comparable long-term outcomes to CABG. Although frequent repeat revascularization could be an inherent weakness of stent-related treatment, it is noteworthy that the observed increase in repeat revascularization after PCI using DES did not appear to translate into an increase in hard endpoints, such as death, myocardial infarction or stroke. Accordingly, the guidelines for the treatment of LMCA stenosis upgraded PCI as a reasonable or considerable treatment in prespecified patients (TABLE 1) [29,30]. Decision making in individual patients: PCI or CABG?
There are fundamental differences in the methodologies of PCI and CABG for treating coronary artery disease. In PCI, the lesion is directly relieved by stents, while in bypass surgery, a graft is placed on the mid-coronary vessel, beyond the lesion, where the epicardial vessel is relatively free of disease. Thus, one of the advantages of CABG over PCI is the achievement of more complete revascularizations, which leads to reductions in future revascularization rates. Although LMCA alone might be considered to be an attractive target for percutaneous intervention because of its large vessel size, short lesion length and lack of tortuosity, LMCA disease often coexists with multivessel disease (e.g., 72.7% in PRECOMBAT, 67.5% in SYNTAX left main subset), thus the choice of PCI or CABG for treatment of unprotected LMCA disease of each case should be based on the comprehensive clinical and anatomical features, and with consideration of the advantages and disadvantages of each procedure. Current standard approach to patients presenting with significant LMCA disease is to have them evaluated by both interventional cardiologists and cardiac surgeons and reach the decision to opt for PCI or surgery by consensus, on the basis of: hemodynamic status of the patient; lesion characteristics; vessel size; the presence of comorbidities; quality of arterial Expert Rev. Cardiovasc. Ther.
Review
Left main coronary artery stenosis
Expert Review of Cardiovascular Therapy Downloaded from informahealthcare.com by Nyu Medical Center on 07/10/15 For personal use only.
Table 1. Current guidelines on PCI for significant unprotected left main coronary artery disease. Guidelines
Class of recommendation
LOE
2011 ACCF/AHA/SCAI Guideline
IIa—For SIHD patients when both of the following are present: . Anatomic conditions associated with a low risk of PCI procedural complications and a high likelihood of good long-term outcome (e.g., a low SYNTAX score [£22], ostial or trunk left main stenosis) . Clinical characteristics that predict a significantly increased risk of adverse surgical outcomes (e.g., STS-predicted risk of operative mortality ‡5%)
B
IIb—For SIHD patients when both of the following are present: . Anatomic conditions associated with a low to intermediate risk of PCI procedural complications and an intermediate to high likelihood of good long-term outcome (e.g., low-intermediate SYNTAX score of 2%)
B
III: HARM—For SIHD patients (versus performing CABG) with unfavorable anatomy for PCI and who are good candidates for CABG
B
I—Left main disease with a SYNTAX score £22
B
IIa—Left main disease with a SYNTAX score 23–32
B
III— Left main disease with a SYNTAX score >32
B
2014 ESC/EACTS Guideline
Ref. [29]
[30]
CABG: Coronary artery bypass graft; LOE: Level of evidence; PCI: Percutaneous coronary intervention; SIHD: Stable ischemic heart disease; STS: The Society of Thoracic Surgeons; SYNTAX: The Synergy between PCI with Taxus and Cardiac Surgery.
and/or venous conduits for grafting; and patient and/or referring physician preferences. Patients must always be fully informed about the potential risks and outcomes of both the surgical and the percutaneous approaches.
the catheterization laboratory. Particularly, because of the critical prognostic importance associated with functionally significant unprotected LMCA, the decision about whether to treat the intermediate LMCA stenosis should not be determined by the coronary angiogram alone.
Functional angioplasty for LMCA disease
For the past several decades, the decision to perform a coronary revascularization has been frequently based on the anatomic severity assessed by coronary angiogram alone. However, the conventional coronary angiogram is only a lumenogram and has critical limitations in assessing the actual functional severity. Furthermore, less than half of patients are noninvasively evaluated for myocardial ischemia before revascularization therapy in the real world practice [31], and the noninvasive functional tests, even when performed, does not provide lesion-specific information and are often inadequate to guide revascularization particularly in patients with complex coronary artery disease, such as LMCA or multivessel disease. One European study demonstrated a significant discordance (35% of all cases) between angiogram and fractional flow reserve (FFR) assessment of stenosis severity after analyzing more than 4000 coronary stenoses [32]. For the LMCA, Hamilos et al. [33] also discovered a considerable discrepancy between the two diagnostic modalities in the evaluation of intermediate stenosis where 29.1% of patients showed a ‘visual functional mismatch’ between angiographic and functional significance. In recent years, a definite paradigm shift has occurred in the treatment of coronary heart disease in that a growing burden of evidence advocates the concept of ‘functional coronary revascularization’ on a lesion level within informahealthcare.com
FFR for LMCA: making decision to treat or not to treat
Routine practice has already changed to include increased use of FFR for LMCA stenting [34,35]. FFR is a pressure-wire-based index used to identify ischemia-producing coronary stenosis and is simply expressed as the ratio between the mean pressure of the aorta and the mean pressure distal to the stenosis in the maximal coronary hyperemic condition. FFR is unique as it is not affected by hemodynamic conditions (e.g., blood pressure, heart rate or contractile state) and is lesion specific, which makes it ideally suited to the assessment of multiple lesions in patients with multivessel and left main disease. An FFR value of >0.75– 0.80, which means less than 20–25% reduction in maximal hyperemic blood flow due to stenotic lesion, has been suggested to be a strong predictor of favorable survival and low event rates in patients with intermediate LMCA disease, making it a useful cut-off value to determine significant LMCA stenosis. In a study involving 213 patients with intermediate LMCA stenosis, 5-year survival rates of 138 patients treated medically with an FFR ‡0.80, and 75 patients treated surgically with an FFR
