Prognostic significance of the left ventricular contractility index in patients with essential hypertension

Abstract

The aim of the study was to assess the relationship between the left ventricular (LV) contractility index, cardiac function and extracardiac organ damage in essential hypertension (EH). We have studied 142 patients (pts) with EH, age 43–52 years, free of signs of heart failure, normal values of the LV ejection fraction and fractional shortening. From M-mode Echo midwall fractional shortening (mFS)(de Simone method), end-systolic stress ESS (Reichek method) were calculated. LV contractility index was assessed as mFS in relation to ESS(mFS/ESS). Early filling velocity (E), late filling velocity (A), E/A ratio, isovolumic relaxation time (IVRT) and deceleration time (DT) were determined by Doppler-Echo. Albuminuria was measured as albumin to creatinine ratio (ACR). Retinal vascular changes were evaluated by direct ophthalmoscopy (Keith-Wagener classification). The prevalence of LV hypertrophy and depressed LV contractility were 68.0 and 43.0%, respectively. The pts with depressed LV contractility index showed high prevalence of LV hypertrophy (86.7% vs 32.3%, p<0.001), especially eccentric hypertrophy (58.0% vs 14.2%, p<0.001). Pts with depressed mFS/ESS had longer IVRT and DT with significant difference in peak E-, A-wave and E/A ratio (IVRT-157.5±9.40 vs 120.0±10.0 ms; 292.5 ±23.4 vs 214.0±6.1 ms; E-60.5±2.43 vs 70.2±1.28 cm/s; A-71.2±2.70 vs 52.0±1.64 cm/s; E/A-0.96 ±0.04 vs 1.20 ±0.08, p<0.01 for all). IVRT and DT showed a strong relation to mFS/ESS (r=−0.67 and r=−0.69, respectively, p<0.01 for both). Moreover hypertensives with depressed mFS/ESS showed early signs of extracardiac damage namely increased ACR (3.2±0.6 vs 1.2 ±0.08, p<0.01) and serum creatinine (3.6±1.2 vs 1.0±0.06 mg%, p<0.05), a higher prevalence of retinopathy (fundoscopy grade II or beyond) compared with subjects with preserved contractility (89.0% vs 40.0%, p<0.001). Furthermore, mFS/ESS was strongly associated with ACR and serum creatinine level in an univariate analysis (r=−0.59 and r=−0.62, respectively, p<0.01 for both) and these associations were still present after stepwise multivariate analysis. Pts with depressed contractility show a higher prevalence of LV hypertrophy, diastolic dysfunction and early signs of extracardiac vascular damage. The evaluation of LV contractility index might improve the prognostic stratification of hypertensive pts and it might be suitable to recognize subset of pts at higher risk.