Abstract 2117: In Hypertensive Dilated Cardiomyopathy Coronary Reserve Impairment Prevents the Improvement in Left Ventricular Systolic Function and Negatively Affects the Long Term Survival
Introduction: In hypertension, left ventricular hypertrophy develops as an adaptative mechanism to compensate for increased afterload in order to maintain wall stress and preserve systolic function. Epidemiological studies identified hypertrophy as an independent factor for mortality. Associated structural changes such as coronary reserve impairment may potentially interfere with this adaptative mechanism and produce pathological hypertrophy. A poorer outcome is likely to result. In patients with hypertensive dilated cardiomyopathy, a shorter survival rate than patients with hypertrophy and preserved systolic funcion is expected.
Hypothesis: The survival in this group of hypertensive dilated cardyomyopathy would be impaired as long as left ventricular function is put in jeopardy by inappropiate coronary reserve.
Methods: We evaluated the role of coronary reserve in the pathophysiological progress of left ventricular hypertrophy by prospectively investigating systolic funcion and survival in patients with hypertensive dilated cardiomyopathy. From 1996 to 2000, 45 hypertensive patients, 30 men, aged 52 +/− 11 years, left ventricular shortening less than 30% were enrolled and followed up until 2006. Coronary flow velocity reserve was assessed by transesophageal Doppler of left anterior descendent coronary artery.
Results: The duration of follow-up was 6.9 +/− 1.9 years. Sixteen patients showed a more than 10% improvement in left ventricular fractional shortening after 17 +/− 6 months of follow-up. Coronary flow velocity reserve was the only variable independently and positively related to the improvement in systolic function. Fourteen patients died after 5.2 +/− 2.0 years. The survival rate was 62% for ten years. Univariate analyses disclosed negative association for coronary flow velocity reserve and left ventricular fractional shortening. The Cox proportional hazards model identified coronary flow velocity reserve (hazard ratio=0.814 95% IC=0.719 – 0.923, P=0.001) as indepent predictor of mortality.
Conclusion: Coronary flow velocity reserve impairment affects negativelly the long term outcome of hypertensive dilated cardiomyopathy, possibly by interfering with the improvement of left ventricular dysfunction.