Correspondence / American Journal of Emergency Medicine 32 (2014) 277–285
285
References
Role of procalcitonin in the diagnosis of infective endocarditis
[1] Ong MEH, Goh K, Fook-Chong S, Haaland B, Wai KL, Koh ZX, et al. Heart rate variability risk score for prediction of acute cardiac complications in ED patients with chest pain. Am J Emerg Med 2013;31(8):1201–7. [2] Malik M. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Eur Heart J 1996;17(3):354–81. [3] Sosnowski M, Clark E, Latif S, Macfarlane PW, Tendera M. Heart rate variability fraction–a new reportable measure of 24-hour R-R interval variation. Ann Noninvasive Electrocardiol 2005;10(1):7–15. [4] Kleiger RE, Stein PK, Bigger JT. Heart rate variability: measurement and clinical utility. Ann Noninvasive Electrocardiol 2005;10(1):88–101. [5] Ozgür S, Ceylan O, Senocak F, Orün UA, Doğan V, Yılmaz O, et al. An evaluation of heart rate variability and its modifying factors in children with type 1 diabetes. Cardiol Young 2013;9:1–8. [6] Ardic I, Kaya MG, Yarlioglues M, Dogdu O, Celikbilek M, Akpek M, et al. Assessment of heart rate recovery index in patients with familial Mediterranean fever. Rheumatol Int 2011;31(1):121–5.
To the Editor,
Regarding “Heart rate variability in patients with chest pain at the ED” To the Editor, In “Heart rate variability in patients with chest pain at the ED”, the authors mentioned that heart rate variability (HRV) has been used to assess autonomic function in different pathological conditions and to investigate the autonomic effects of drugs, etc. HRV has also been reported as a sensitive indicator of autonomic dysfunction in alcoholics and in smokers. These are interesting points that indicate the potential utility of HRV and its association with various diseases. Also mentioned in this letter are factors that have impact on HRV. These factors may include length of recording of electrocardiogram (ECG), noise level in ECG signals, demographic variation, and many others. Current commercially available HRV tools can only interpret sinus rhythms, and they might not handle well ECG recordings with sustained arrhythmias or large segments of artifacts. Unfortunately, patients with non-sinus rhythms are usually at high risk for acute cardiac complications. The authors also raise the issue of the effect of comorbid diseases and medications on HRV analysis. All these questions represent challenges as well as opportunities for further research in this field. Further analysis of data from large-scale observational cohort studies will be useful in this respect.
We have read with interest the recently published article titled “Role of procalcitonin (PCT) in the diagnosis of infective endocarditis (IE): a meta-analysis” by Yu et al [1]. They aimed to evaluate the diagnostic value of PCT in describing IE. They only included 6 studies in their metaanalysis. They found different and heterogeneous results in every study included in their analysis: there were variable results with respect to PCT sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios. First, the 6 studies in the meta-analysis differ in terms of median age. Stucker et al [2] reported that the diagnostic level of PCT for infection could vary according to age. Therefore, one challenge is the need for more research to describe the relationship between infection and IE. Another challenge is that 3 different methods were used in the 6 studies, each with different cutoff values for PCT. Second, PCT can have false-negative values in subacute IE cases. Subacute forms of IE or prosthetic valve IE may have different presentations because of biofilm and low-level inflammatory responses [3]. It would have been better if the authors had mentioned these conditions as limitations of this meta-analysis. Lastly, PCT is affected by a variety of infectious agents. In comparisons of gram-negative agents with gram positives, PCT levels are found to be higher in gram negatives [4]. A previous study by Kocazeybek et al [5] concluded that the median values of serum PCT were found to be higher in cases with IE and non-IE related to gramnegative bacteria than in those related to gram-positive bacteria. However, most of bacteria included in these studies were gram positive. This can bias the diagnostic value of PCT in IE. Therefore, it would have been more accurate if the authors had compared PCT levels according to infectious agents in this meta-analysis. In conclusion, further studies are required to determine the relationship between PCT and IE. It is important that PCT be considered along with other independent variables (eg, age, bacterial agents, subacute IE, and acute IE) to provide the required information. Mustafa Hatipoglu, MD Asim Ulcay, MD Ergenekon Karagoz, MD Vedat Turhan, MD Department of Infectious Diseases and Clinical Microbiology GATA Haydarpasa Training Hospital Istanbul, Turkey E-mail address: [email protected] http://dx.doi.org/10.1016/j.ajem.2013.12.004
Marcus Eng Hock Ong, MBBS Nan Liu, PhD Department of Emergency Medicine Singapore General Hospital 169608 Singapore E-mail addresses: [email protected] [email protected]
http://dx.doi.org/10.1016/j.ajem.2013.11.049
References [1] Yu CW, Juan LI, Hsu SC, Chen CK, Wu CW, Lee CC, et al. Role of procalcitonin in the diagnosis of infective endocarditis: a meta-analysis. Am J Emerg Med 2013;31(6):935–41. [2] Stucker F, Herrmann F, Graf JD, Michel JP, Krause KH, Gavazzi G. Procalcitonin and infection in elderly patients. J Am Geriatr Soc 2005;53(8):1392–5. [3] Schuetz P, Albrich W, Mueller B. Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future. BMC Med 2011;9:107. [4] Charles PE, Ladoire S, Aho S, Quenot JP, Doise JM, Prin S, et al. Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either gram negative or gram positive bacteria. BMC Infect Dis 2008;8:38. [5] Kocazeybek B, Kucukoglu S, Oner YA. Procalcitonin and C-reactive protein in infective endocarditis: correlation with etiology and prognosis. Chemotherapy 2003;49(1–2):76–84.
285
References
Role of procalcitonin in the diagnosis of infective endocarditis
[1] Ong MEH, Goh K, Fook-Chong S, Haaland B, Wai KL, Koh ZX, et al. Heart rate variability risk score for prediction of acute cardiac complications in ED patients with chest pain. Am J Emerg Med 2013;31(8):1201–7. [2] Malik M. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Eur Heart J 1996;17(3):354–81. [3] Sosnowski M, Clark E, Latif S, Macfarlane PW, Tendera M. Heart rate variability fraction–a new reportable measure of 24-hour R-R interval variation. Ann Noninvasive Electrocardiol 2005;10(1):7–15. [4] Kleiger RE, Stein PK, Bigger JT. Heart rate variability: measurement and clinical utility. Ann Noninvasive Electrocardiol 2005;10(1):88–101. [5] Ozgür S, Ceylan O, Senocak F, Orün UA, Doğan V, Yılmaz O, et al. An evaluation of heart rate variability and its modifying factors in children with type 1 diabetes. Cardiol Young 2013;9:1–8. [6] Ardic I, Kaya MG, Yarlioglues M, Dogdu O, Celikbilek M, Akpek M, et al. Assessment of heart rate recovery index in patients with familial Mediterranean fever. Rheumatol Int 2011;31(1):121–5.
To the Editor,
Regarding “Heart rate variability in patients with chest pain at the ED” To the Editor, In “Heart rate variability in patients with chest pain at the ED”, the authors mentioned that heart rate variability (HRV) has been used to assess autonomic function in different pathological conditions and to investigate the autonomic effects of drugs, etc. HRV has also been reported as a sensitive indicator of autonomic dysfunction in alcoholics and in smokers. These are interesting points that indicate the potential utility of HRV and its association with various diseases. Also mentioned in this letter are factors that have impact on HRV. These factors may include length of recording of electrocardiogram (ECG), noise level in ECG signals, demographic variation, and many others. Current commercially available HRV tools can only interpret sinus rhythms, and they might not handle well ECG recordings with sustained arrhythmias or large segments of artifacts. Unfortunately, patients with non-sinus rhythms are usually at high risk for acute cardiac complications. The authors also raise the issue of the effect of comorbid diseases and medications on HRV analysis. All these questions represent challenges as well as opportunities for further research in this field. Further analysis of data from large-scale observational cohort studies will be useful in this respect.
We have read with interest the recently published article titled “Role of procalcitonin (PCT) in the diagnosis of infective endocarditis (IE): a meta-analysis” by Yu et al [1]. They aimed to evaluate the diagnostic value of PCT in describing IE. They only included 6 studies in their metaanalysis. They found different and heterogeneous results in every study included in their analysis: there were variable results with respect to PCT sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios. First, the 6 studies in the meta-analysis differ in terms of median age. Stucker et al [2] reported that the diagnostic level of PCT for infection could vary according to age. Therefore, one challenge is the need for more research to describe the relationship between infection and IE. Another challenge is that 3 different methods were used in the 6 studies, each with different cutoff values for PCT. Second, PCT can have false-negative values in subacute IE cases. Subacute forms of IE or prosthetic valve IE may have different presentations because of biofilm and low-level inflammatory responses [3]. It would have been better if the authors had mentioned these conditions as limitations of this meta-analysis. Lastly, PCT is affected by a variety of infectious agents. In comparisons of gram-negative agents with gram positives, PCT levels are found to be higher in gram negatives [4]. A previous study by Kocazeybek et al [5] concluded that the median values of serum PCT were found to be higher in cases with IE and non-IE related to gramnegative bacteria than in those related to gram-positive bacteria. However, most of bacteria included in these studies were gram positive. This can bias the diagnostic value of PCT in IE. Therefore, it would have been more accurate if the authors had compared PCT levels according to infectious agents in this meta-analysis. In conclusion, further studies are required to determine the relationship between PCT and IE. It is important that PCT be considered along with other independent variables (eg, age, bacterial agents, subacute IE, and acute IE) to provide the required information. Mustafa Hatipoglu, MD Asim Ulcay, MD Ergenekon Karagoz, MD Vedat Turhan, MD Department of Infectious Diseases and Clinical Microbiology GATA Haydarpasa Training Hospital Istanbul, Turkey E-mail address: [email protected] http://dx.doi.org/10.1016/j.ajem.2013.12.004
Marcus Eng Hock Ong, MBBS Nan Liu, PhD Department of Emergency Medicine Singapore General Hospital 169608 Singapore E-mail addresses: [email protected] [email protected]
http://dx.doi.org/10.1016/j.ajem.2013.11.049
References [1] Yu CW, Juan LI, Hsu SC, Chen CK, Wu CW, Lee CC, et al. Role of procalcitonin in the diagnosis of infective endocarditis: a meta-analysis. Am J Emerg Med 2013;31(6):935–41. [2] Stucker F, Herrmann F, Graf JD, Michel JP, Krause KH, Gavazzi G. Procalcitonin and infection in elderly patients. J Am Geriatr Soc 2005;53(8):1392–5. [3] Schuetz P, Albrich W, Mueller B. Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future. BMC Med 2011;9:107. [4] Charles PE, Ladoire S, Aho S, Quenot JP, Doise JM, Prin S, et al. Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either gram negative or gram positive bacteria. BMC Infect Dis 2008;8:38. [5] Kocazeybek B, Kucukoglu S, Oner YA. Procalcitonin and C-reactive protein in infective endocarditis: correlation with etiology and prognosis. Chemotherapy 2003;49(1–2):76–84.
