Implications of exercise test modality on modern prognostic markers in patients with known or suspected coronary artery disease: treadmill versus bicycle.

BACKGROUND: Important modern prognostic markers such as heart rate recovery (HRR), chronotropic index, delayed systolic blood pressure (SBP) response and Duke treadmill score (DTS) have been evaluated by treadmill exercise testing. Their value in bicycle exercise testing is unclear. METHODS: Patients (n=211, age 64+/-10; 75% male) with known or suspected coronary artery disease randomly underwent either bicycle (n=105) or treadmill (n=106) exercise electrocardiography. They were matched for age, gender, body mass index, hypertension, smoking, lipid status, prevalence of diabetes, medication, haemoglobin level, extent of coronary artery disease and left ventricular ejection fraction. RESULTS: Despite a higher peak heart rate (pHR) patients stressed by treadmill had a slower drop in HR during the early phase of recovery with a significantly higher rate of abnormal HRR (pHR; HR 1 min into recovery < or =12 bpm) with 37% in treadmill versus 19% in bicycle (P=0.004). Abnormally delayed SBP response [(SBP 1 min into recovery/SBP 3 min into recovery) >1.0] was also more common in treadmill (41%) compared to bicycle (12%, P<0.001). However, the rate of chronotropic incompetence [(pHR - rest HR)/(220 - age - rest HR) <0.8] was significantly lower in treadmill than in bicycle (60 versus 76%, P<0.001). Mean DTS was also significantly higher in treadmill compared to bicycle (4.8+/-6.5 versus 3.6+/-5.1, P=0.03) mainly due to the higher workload achieved when patients were stressed by treadmill (8.5+/-2.5 versus 6.1+/-1.5 metabolic equivalents, P<0.001). CONCLUSIONS: Further adjustment is needed prior to routine incorporation of these important measures into interpretation of bicycle exercise testing

Incidence, time course, and predictors of early malignant ventricular arrhythmias after non-ST-segment elevation myocardial infarction in patients with early invasive treatment.

AIMS: The incidence of non-ST-segment elevation myocardial infarction (NSTEMI) is increasing. With the limited intensive care facilities, knowledge of the total risk and predictors of acute life-threatening arrhythmias is of major interest to guide the decision on the intensity of care at the time of admission. METHODS AND RESULTS: We continuously monitored 588 consecutive patients with NSTEMI admitted to the coronary care unit of a primary and tertiary care centre for malignant ventricular arrhythmias requiring defibrillation. Ninety-seven per cent of the patients underwent coronary angiography during the index hospital admission. Total rate of malignant ventricular arrhythmias and mortality was 2.6% (n=15) and 3.6% (n=21), respectively. More than two-thirds of arrhythmias occurred within the first 12 h after onset of symptoms. In a bootstrapped multivariable regression analysis, the only factor associated with the occurrence of malignant ventricular arrhythmia was higher white blood cell count on admission. Popular risk assessment tools such as Thrombolysis in Myocardial Infarction, Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy, and Predicting Risk of Death in Cardiac disease Tool were predictive of mortality but not of early arrhythmia. CONCLUSION: Patients with NSTEMI treated aggressively with early revascularization are at low risk for developing life-threatening arrhythmias. The occurrence of such events remains difficult to predict. The role of baseline inflammatory status as a determinant merits further investigations

Correlation of exercise capacity with high-sensitive C-reactive protein in patients with stable coronary artery disease.

BACKGROUND: There is growing evidence for the association between physical activity and systemic inflammatory markers in healthy individuals and populations with a low prevalence of coronary artery disease (CAD). However, the association between fitness and CRP in patients with stable CAD treated with medications known to influence the inflammatory response, such as statins and aspirin, is not well known. METHODS: We prospectively enrolled 209 patients with angiographically documented CAD (161 men; age 63 +/- 10 years; 1-/2-/3-vessel disease in 42%, 34%, and 24% of patients, respectively; left ventricular ejection fraction 60% +/- 13%). Fitness level was assessed by maximal exercise testing. CRP was measured in all patients using high-sensitivity immunoassay. RESULTS: Fitness level was inversely correlated with natural log-transformed CRP level (r = -0.28, P < .001). After multivariate linear regression adjustment for age, sex, body mass index, waist circumference, smoking status, educational level, diabetes, hypertension, modality of exercise testing, exercise-induced ischemia, extent of CAD, medication use, leukocyte count, hemoglobin, renal function, glucose level, and cholesterol level, exercise capacity remained inversely correlated with CRP level (beta = -.226, P = .001). Other covariates associated with CRP remaining in the final model were leukocyte count (beta = .348), pack-years of smoking (beta = .185), diabetes status (beta = -.201), hemoglobin concentration (beta = -.187), and high-density lipoprotein cholesterol level (beta = -.149). CONCLUSIONS: These results indicate that exercise capacity is inversely correlated with CRP level in patients with known stable CAD irrespective of extent of CAD and standard medication for secondary prevention