DIPYRIDAMOLE-ECHOCARDIOGRAPHY FOR DIAGNOSIS OF COEXISTENT CORONARY-ARTERY DISEASE IN HYPERTROPHIC CARDIOMYOPATHY

The recognition of coexistent coronary artery disease (CAD) in patient s with hypertrophic cardiomyopathy may be difficult by noninvasive tes ting based upon electrocardiographic changes or perfusion defects. Dip yridamole-stress echocardiography has proved a sensitive and highly sp ecific test for noninvasive diagnosis of CAD in various patient subset s. To establish the feasibility, safety, and diagnostic accuracy of di pyridamole-stress echocardiography in patients with hypertrophic cardi omyopathy, we performed high-dose dipyridamole testing (up to 0.84 mg/ kg over 10 minutes) in 88 patients with hypertrophic cardiomyopathy (6 3 men; mean age +/- SD, 46 +/- 17 years). A subset of 60 patients was referred for coronary angiography independently of test results; CAD w as defined as greater than or equal to 50% diameter narrowing in at le ast 1 major coronary vessel. Dipyridamole echocardiography/electrocard iography testing was completed in all patients, with no limiting side effects or adverse reactions, In the subgroup of 60 patients with coro nary angiography (14 with and 46 without CAD), chest pain occurred in 18 patients (8 with and 10 without CAD, p = NS); ST-segment depression greater than or equal to 2 mm from baseline in 28 (7 with and 21 with out CAD, p NS); and transient dyssynergy in 10 patients (10 with and n one without CAD, p <0.0001). Assuming the transient regional dyssynerg y to be the only criterion of positivity, the dipyridamole echocardiog raphy test showed 71% sensitivity, 100% specificity, 100% positive pre dictive value, and 93% diagnostic accuracy for diagnosis of angiograph ically assessed CAD. We conclude that high-dose dipyridamole echocardi ography testing may be considered a feasible and accurate tool for the noninvasive diagnosis of CAD in patients with hypertrophic cardiomyop athy.