Glycoprotein IIIa gene polymorphism and coronary artery disease.

OBJECTIVE: Prevalence of glycoprotein IIIa gene polymorphisms (PIA2) has been reported to be elevated in persons who die of sudden death. PIA2 has been suggested as contributing to the development of atherosclerosis via coronary plaque rupture and thrombus formation. In this prospective study, we investigated the correlation between the PIA2 polymorphism, atherosclerotic plaque burden, and its prognostic significance. METHODS AND RESULTS: One hundred and seventy-eight patients (mean age 51 +/- 9.6 years) suspected to have atherosclerotic coronary artery disease underwent a coronary angiography and were evaluated for gene polymorphisms. Patients were followed up for 4 years for major adverse cardiac events (MACE). Thirty-eight patients (21%) had the PIA2 polymorphism.There was no statistically significant correlation between presence of atherosclerotic plaque burden, severity of coronary artery stenosis, and glycoprotein genotype. During the follow-up there were no significant differences between the 2 groups with regard to MACE. Any cause of death and cardiovascular death were higher in patients with PIA2 polymorphism but these differences were not significant. On univariate analysis, smoking, presence of severe coronary artery disease, and presence of myocardial infarction were correlated with elevated risk of MACE; presence of atypical angina was correlated with fewer MACE. On multivariate analysis, smoking was an independent risk factor for a MACE. On univariate or multivariate analysis, there was no relation between the PIA2 polymorphism and a MACE. CONCLUSIONS: The glycoprotein IIb/IIIa genotype was not shown to indicate the presence of atherosclerotic plaque. There was no correlation between the genotype and plaque vulnerability.

The clinical significance of aspirin resistance in patients with chest pain.

BACKGROUND: There are conflicting data in the literature about the clinical significance of aspirin resistance. HYPOTHESIS: We aimed to prospectively evaluate the prevalence of biochemical aspirin resistance in patients on aspirin therapy who were admitted to the emergency clinic with chest pain. We also aimed to evaluate the relation between acute coronary syndromes (ACS) and aspirin resistance. METHODS: A total of 338 patients were included in the study. Platelet reactivity was measured with the PFA-100 system (Dade Behring Inc, Deerfield, IL). Aspirin resistance determined by the PFA-100 was defined as a normal collagen and/or epinephrine closure time despite aspirin treatment (<165 s). RESULTS: Patients were divided into 4 groups: stable angina pectoris (SAP), unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI), ST-elevation myocardial infarction (STEMI), and rule out ACS. Aspirin resistance was found in 81 (24%) patients in all groups. Patients with ACS had significantly more aspirin resistance than patients with rule out ACS or patients with SAP (P < .001). In the SAP group, 31 (19.6%) patients; in the UA/NSTEMI group, 19 (35.8%) patients; in the STEMI group, 14 (50%) patients; and in the rule out ACS group, 17 (17.2%) patients had aspirin resistance (P < .001). In the multivariate analysis, cardiac biomarker elevation on admission to emergency department and platelet count appeared as independent factors predictive of aspirin resistance. CONCLUSIONS: We demonstrated that incidence of aspirin resistance was significantly higher in patients who were finally diagnosed as ACS, especially in aspirin-taking patients admitted to the emergency clinic with STEMI.

Adenosine-induced ventricular arrhythmias in patients with supraventricular tachycardias.

BACKGROUND: Adenosine is widely used for the diagnosis and the termination of supraventricular arrhythmias. There are many case reports and few series about the proarrhythmic potential of adenosine. We sought to evaluate the proarrhythmic potential of adenosine used to terminate the supraventricular arrhythmias. METHODS: The records of all patients that received adenosine for the termination of supraventricular tachycardia were reviewed retrospectively and those with a continuous electrocardiographic (ECG) recording during adenosine administration were included to the study. RESULTS: Our search identified 52 supraventricular episodes of 46 patients with a continuous ECG recording during adenosine administration. Following adenosine administration, premature ventricular contraction (PVC) or ventricular tachycardia (VT) developed in 22 (47.8%) patients and in 26 (50%) tachycardia episodes. No patient had a sustained VT. Nonsustained VT developed in eight (17.4%) patients. All VT episodes were polymorphic, short, and self-terminating. When the basal and demographic properties of patients with PVC or VT and those without PVT or VT were compared, there was no significant difference. CONCLUSIONS: Adenosine is a quite safe and effective drug for the termination of narrow QRS complex tachycardia but it often induces nonsustained VT or PVC that are clinically insignificant in the absence of other accompanying heart disease.

Prevalence and predictors of arrhythmia in end stage renal disease patients on hemodialysis.

BACKGROUND: Sudden death is common in end-stage renal disease (ESRD). Cardiac arrhythmia is observed frequently in patients with ESRD and is thought to be responsible for this high rate of sudden death. This study investigated the prevalence and the predictors of arrhythmia in patients on maintenance dialysis. METHODS: Ninety-four patients on hemodialysis program were enrolled in the study. Routine laboratory results were noted. Arrhythmia, periods of silent ischemia, and heart-rate variability analyses were obtained from 24-hour Holter monitor recordings. Corrected QT (QTc) dispersion was calculated from 12-lead surface EKG. Echocardiographic and tissue Doppler examinations were performed on interdialytic days as well. Ventricular arrhythmia was classified according to Lown classification; classes 3 and above were accepted as complex ventricular arrhythmia (CVA). RESULTS: The mean age was 52.5+/-13.2 years; 44 (46.8%) were women. Ventricular premature contractions were detected in 80 (85.1%) patients, of whom 35 (37.2%) were classified as complex ventricular arrhythmia (CVA). Coronary artery disease, hypertension, and QTc dispersion appeared as independent factors predictive of CVA development. Atrial premature contractions (APC) were detected in 53 patients (56.4%) and supraventricular arrhythmia in 15 (16%) patients; all were identified as atrial fibrillation. Duration of dialysis therapy was found as an independent predictor of APC. CONCLUSION: Arrhythmia is frequently observed in ESRD patients receiving hemodialysis and may be responsible for the high rate of sudden mortality. Hypertension, CAD, and QTc dispersion are independent predictors of CVA, and duration of dialysis therapy is an independent factor affecting APC development in these patients.

Aortic elastic properties and left ventricular diastolic function in white-coat hypertensive individuals.

OBJECTIVES: Although white-coat hypertension may be present in 25% or more of hypertensive individuals, its prognostic significance and predisposition to end organ damage is unknown. To evaluate whether white-coat hypertension is associated with end organ damage, we compared prognostically relevant measures of target-organ damage among 35 individuals with white-coat hypertension and age and sex-matched groups of sustained hypertension and normotensive individuals classified by clinical and 24-h ambulatory blood pressures. METHODS: We evaluated left ventricular diastolic function and aortic elastic properties of 35 individuals with white-coat hypertension, 50 patients with sustained hypertension, and 35 normotensive healthy volunteers using transthoracic Doppler echocardiography. None of the study participants with sustained hypertension and white-coat hypertension, who were newly diagnosed and never treated, had any systemic disease or coronary risk factor except hypertension. RESULTS: Age, sex, and body mass indexes were similar among the three groups. Left ventricular diastolic function was more significantly impaired in the sustained hypertension and white-coat hypertension groups than in the control group, but it was not significantly different between the white-coat hypertension and sustained hypertension groups. Aortic distensibility was significantly lower, and aortic stiffness index was significantly higher in the sustained hypertension group than in the white-coat hypertension and control groups. Furthermore, aortic elastic properties were slightly impaired in the white-coat hypertension group compared with those in the control group. We also found a significant correlation between aortic elastic properties and left ventricular diastolic function. CONCLUSIONS: White-coat hypertension may alter left ventricular diastolic function and aortic elastic properties. These alterations, however, might not be as remarkable as those caused by sustained hypertension. In this respect, individuals with white-coat hypertension are not at such a risk for end organ damage as patients with sustained hypertension.

Prevalence of coronary artery disease in patients undergoing valvular operation due to rheumatic involvement.

OBJECTIVE: Rheumatic heart disease is still a major health problem in developing countries. The impact of coronary artery disease (CAD) on or its relation to rheumatic fever is not well established. We aimed to evaluate the prevalence of CAD and atherosclerotic risk factors in patients who underwent valvular surgery due to rheumatic heart disease. METHODS: The records of 346 patients who had undergone rheumatic valvular surgery in a university hospital between 1996 and 2002 were evaluated. RESULTS: Coronary angiography was performed in 218 (63%) patients, of whom 41 (18.8%) had CAD. The mean age of the patients having CAD and normal coronary arteries were 57.3 and 50.5 years respectively (p<0.001). In the study population patients with CAD had significantly increased prevalence of diabetes mellitus (14.6% vs. 4.5%; p=0.02), hypertension (36.6% vs. 16.4%; p=0.003), smoking (51.2% vs. 23.2%; p=0.001) and family history of CAD (39.5% vs. 20.0%; p=0.01) compared to patients with normal coronary arteries. However, the prevalence of dyslipidemia was similar in both groups (45.9% vs. 36.4%; p=0.1). CONCLUSION: These findings suggest that coronary artery disease prevalence in rheumatic valvular disease patients is similar to the normal population of same age. In cases where invasive assessment of valvular lesions is not indicated we suggest coronary angiography to be performed only in patients having clinical suspicion of CAD or multiple risk factors.