Failure to raise blood pressure during exercise is a poor prognostic sign in patients with hypertrophic non-obstructive cardiomyopathy

Abstract

Sudden cardiac death is a well-documented complication of hypertrophic cardiomyopathy and additionally, failure to raise blood pressure (BP) during exercise has been associated with a poor outcome. The present study group comprised 58 patients with hypertrophic non-obstructive cardiomyopathy (HNCM) who were receiving β-blocker therapy. All patients underwent submaximal exercise radionuclide ventriculography (RNVG) to evaluate left ventricular (LV) function at both rest and peak exercise. Patients were divided into 2 groups based on the increase in systolic BP during exercise (ie, group A <30% or group N ≥30% of resting systolic BP) and were involved in long-term follow-up (10.4±4.0 years). Group A comprised 29% of the subjects. Age and workload at peak exercise were similar in the 2 groups. LV end-diastolic dimension was smaller and the interventricular septum was thicker in group A. LV ejection fraction on RNVG was similar in the 2 groups at rest and at peak exercise. During the follow-up period, more patients in group A than group N suffered syncopal attack (29% vs 5%, p<0.05) and cardiac sudden death (24% vs 2%, p<0.05). Patients with HNCM whose BP fails to rise during exercise have a poor prognosis.