Higher prevalence of cardiovascular events among patients with abnormal atrial depolarization and coronary artery disease at 18 months' post-exercise tolerance testing.

Abnormal atrial depolarization, denoted as interatrial block (IAB; P wave >110 ms), is associated with myocardial ischemia during exercise. The authors conducted an 18-month follow-up for cardiovascular events in 31 consecutive patients with IAB and 60 controls without IAB at rest; participants had coronary artery disease and hypertension and had undergone coronary angiography following positive exercise tolerance test (ETT) results. Atrial fibrillation and need for repeat ETT and coronary artery revascularization were significant with IAB (77.4% vs 20%; P<.001). In patients with such events, IAB, left atrial dilatation, left ventricular hypertrophy, increased left ventricular end-diastolic volume, poorer Duke prognostic treadmill (DPT) scores, and significant coronary artery stenoses were predominant. IAB (hazard ratio [HR], 4.9; 95% confidence interval [CI], 1.3-19.7; P=.02) and DPT scores (HR, 0.84; 95% CI, 0.72-0.98; P=.03) were independently associated with these events. At 18 months' follow-up, IAB at rest was associated with cardiovascular events among those with known coronary artery disease and hypertension.