Prognostic value of systemic blood pressure response during exercise in community-based patient population with hypertrophic cardiomyopathy

OBJECTIVES The present study was designed to prospectively evaluate the prognostic relevance of abnormal blood pressure response to exercise (ABPR), defined as hypotension or failed blood pressure increase (<20 mm Hg) with exercise, in community-based hypertrophic cardiomyopathy (HCM) population representative of the overall disease spectrum. BACKGROUND Abnormal blood pressure response to exercise has been proposed as marker for hemodynamic instability and increased risk for disease-related mortality in highly selected patient populations with HCM. METHODS The study population comprised 126 patients (aged 42 ± 14 years) who underwent maximal symptom-limited cycloergometer exercise testing as part of the standard evaluation at our institution, and who were followed systematically for 4.7 ± 3.7 years after testing. RESULTS Of the 126 study patients, 98 (78%) had normal blood pressure response during exercise, whereas the other 28 (22%) had ABPR, including nine with hypotension and 19 with failed blood pressure rise. During the follow-up period, nine patients (7%) died of HCM-related causes (three suddenly and six heart failure–related), of whom four had ABPR. In those patients aged ≤50 years, survival analysis after exercise testing showed significantly increased risk for cardiovascular mortality associated with ABPR compared with normal exercise response (p = 0.04), with an odds ratio of 4.5 (95% confidence interval: 1.1, 20.1). However, ABPR showed low positive predictive accuracy for cardiovascular mortality (i.e., 14%), whereas negative predictive accuracy was high (i.e., 95%). CONCLUSIONS hypotensive blood pressure response during exercise occurred in over 20% of community-based patient cohort with HCM, and was associated with adverse long-term prognosis in patients <50 years old. However, the positive predictive accuracy of this blood pressure response is too low to justify modifications of clinical management or to allow identification of the high-risk patient based solely on an abnormal test result. By virtue of its high negative predictive accuracy for HCM-related mortality, the blood pressure response to exercise appears to be most valuable (in conjunction with the absence of other well recognized risk factors) as screening test for the identification of low-risk subsets of patients.