Prognostic value of systemic blood pressure response during exercise in a 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 a community-based hypertrophic cardiomyopathy (HCM) population representative of the overall disease spectrum.

Background: Abnormal blood pressure response to exercise has been proposed as a 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 a 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 < or =50 years, survival analysis after exercise testing showed a significantly increased risk for cardiovascular mortality associated with ABPR compared with a 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: A hypotensive blood pressure response during exercise occurred in over 20% of a 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 a screening test for the identification of low-risk subsets of patients.