Losartan improves exercise tolerance in patients with diastolic dysfunction and a hypertensive response to exercise

OBJECTIVES The aim of the study was to test the hypothesis that angiotensin II (Ang II ) blockade would improve exercise tolerance in patients with diastolic dysf unction and a marked increase in systolic blood pressure (SBP) during exerc ise. BACKGROUND Diastolic dysfunction may be exacerbated during exercise, especially if the re is a marked increase in SEP. Angiotensin II may contribute to the hypert ensive response to exercise and impair diastolic performance. METHODSWe performed a randomized, double-blind, placebo-controlled, crossov er study of two weeks of losartan (50 mg q.d.) on exercise tolerance and qu ality of life. The subjects were 20 patients, mean age 64 +/- 10 years with normal left ventricular systolic function (EF >50%), no ischemia on stress echocardiogram, mitral flow velocity E/A <1, normal resting SEP (<150 mm H g), and a hypertensive response to exercise (SBP >200 mm Hg). Exercise echo cardiograms (Modified Bruce Protocol) and the Minnesota Living With Heart F ailure questionnaire were administered at baseline, and after each two-week treatment period, separated by a two-week washout period. RESULTS Resting blood pressure (BP) was unaltered by placebo or losartan. During co ntrol, patients were able to exercise for 11.3 +/- 2.5 (mean +/- SD) min, w ith a peak exercise SEP of 226 +/- 24 mm Hg. After two weeks of losartan, b aseline BP was unaltered, but peak SEP during exercise decreased to 193 +/- 27 mm Hg (p < 0.05 vs. baseline and placebo), and exercise time increased to 12.3 +/- 2.6 min (p < 0.05 vs, baseline and placebo). With placebo, ther e was no improvement in exercise duration (11.0 +/- 2.0min) or peak exercis e SEP (217 +/- 26 mm Hg). Quality of life improved with losartan (18 +/- 22 , p < 0.05) compared to placebo (22 +/- 26). CONCLUSIONS In patients with Doppler evidence of diastolic dysfunction at rest and a hy pertensive response to exercise, Ang II receptor blockade blunts the hypert ensive response to exercise, increases exercise tolerance and improves qual ity of life. (C) 1999 by the American College of Cardiology.