P3835Improvement of myocardial energetic efficiency during treatment in hypertensive patients: the life study

Abstract

Abstract Background Myocardial energetic efficiency (MEE) per unit of left ventricular (LV) mass significantly predicts composite of cardiovascular (CV) events in treated hypertensive patients and specifically heart failure in an event-free population-based cohort with normal ejection fraction, independently of LV hypertrophy (LVH). Purpose To investigate whether MEEi changes over time in treated hypertensive patients, and whether different treatments have different effects. Methods From the Losartan Intervention For Endpoint study (LIFE Echo Sub-study) we selected 744 hypertensive patients (age 66±7 years; 45% women) with LVH at ECG, without atrial fibrillation, previous or incident myocardial infarction and with normal echocardiographic ejection fraction (>50%). MEE was estimated as the ratio of stroke work to the “double” product of heart rate times systolic blood pressure (BP), simplified as the ratio of stroke volume to heart rate, as previously reported. MEE was normalized for LVM (MEEi) and analyzed in quartiles at baseline and at the end treatment, according to an “intention-to-treat” protocol. Results Age and proportion of women were not significantly different from the highest to the lowest quartiles (from 65±7 to 66±7 years, p for trend=0.352; from 45% to 42%, p=0.946, respectively), whereas diastolic blood pressure (from 97±8 to 100±9 mmHg, p=0.006), prevalence of obesity (from 14 to 31%, p=0.001) and diabetes (from 4 to 14%, 0.004) progressively increased. Prevalence of concentric LV geometry and echocardiographic LVH also progressively increased from the highest to the lowest quartile (from 14 to 70%, and 61 to 90%, both p<0.0001). MEEi increased over time (p<0.007), independently of initial diastolic BP, diabetes and obesity, significantly more in patients treated with atenolol than with losartan (p<0.0001) (Figure), due to both increased stroke volume and decreased heart rate (both p<0.0001). Figure 1 Conclusions In a randomized clinical study, MEEi improves with anti-hypertensive therapy. Improvement is more evident in patients with atenolol than with losartan-based treatment, possibly providing pathophysiologic explanation of the comparable performance in prevention of ischemic heart disease previously reported in the LIFE study.