Prevalence and distribution of coronary disease in claudicants using 12-lead precordial stress electrocardiography

Aims: to evaluate the prevalence of coronary artery disease (CAD) by means of modified stress electrocardiography in patients presenting with intermittent claudication. Methods: three hundred consecutive patients (188 male) with intermittent claudication (post-exercise ankle brachial index < 0.8), and 100 age and sex-matched controls, were assessed for CAD with resting and stress 12-lead-precordial ECG. A history of angina and previous myocardial infarction (MI) was recorded. Exclusion criteria: recent (<1 month) MI, unstable angina; prior coronary intervention; arrhythmias; conduction abnormalities; uncontrolled hypertension; heart failure, digoxin therapy, and inability to perform tests. Results: based on antecedent angina, MI and abnormal resting ECG, CAD prevalence was 47% in claudicants and 6% in controls; on 12-lead-precordial ECG stress testing, CAD prevalence was 46% (95% CI: 40.1-51.7%) in claudicants and 11% (95% CL 4.8-17.2%) in controls (both p < 0.0001). Only 67% of claudicants (n = 141) with antecedent angina, MI or an abnormal resting ECG, met the criteria of CAD on stress testing; also 28% of claudicants without antecedent angina, MI and a normal resting ECG (n = 159) had evidence of CAD. The odds ratio for CAD in claudicants was 6.9. Based on 12-lead-precordial ECG stress testing we detected the presence of: one-, two- and three-vessel disease in 14.7% (95% CL 10.6-18.7%),19% (95% CI: 14.5-23.5%) and in 12.3% (95% CI: 8.6-16%) of claudicants; and in 8,3 and 0% of controls, respectively. Conclusions: forty six percent of patients with intermittent claudication had concomitant CAD, and 31% two- or three-vessel disease. In the presence of claudication the odds ratio for CAD is 6.9 (95% CI: 3.5-13.4) and for two- or three-vessel disease 14.8. Non-invasive modified stress electrocardiography by enabling identification of those with multi-vessel CAD and thus by providing cardiac risk stratification may help bridge the gap between clinical evaluation and invasive coronary imaging.