Silent ST depression and cardiovascular end-organ damage in newly found, older hypertensives

Abstract

In hypertension, both reduced vascular supply and increased cardiac demand contribute to the development of (silent) myocardial ischemia. Our aim was to determine the prevalence of ST-segment depression and to analyze contributing factors in asymptomatic, previously untreated, older hypertensives. From a population survey, in 184 patients with mild hypertension (4 times systolic blood pressure ≥160 mm Hg and/or diastolic blood pressure ≥95 mm Hg), 60 to 75 years of age, cardiovascular end-organ damage was measured. Episodes of ST-segment depression were measured by 48-hour ambulatory Holter monitoring and were observed in 21 hypertensives (12%). They showed a significantly higher combined far-wall intima-media thickness of carotid and femoral arteries and more arterial plaques as measured by B-mode ultrasound compared with hypertensives without ST depression (0.00098±0.00021 versus 0.00088±0.00016 mm and 5.2±3.7 versus 3.7±2.8 plaques, P<0.05, respectively), whereas left ventricular mass index was not different (111±18 versus 104±24 g/m2.; P=0.18, respectively). In hypertensives with transient ST-segment depression, a significant relation was found between left ventricular mass and ischemic burden (r=0.51, P=0.02). Approximately 1 of 8 unselected and previously untreated older hypertensives show asymptomatic ST-segment depression, suggestive of silent myocardial ischemia. These data suggest that vascular factors mainly determine the occurrence of ischemic ST-segment depression and cardiac factors determine the ischemic burden in older hypertensives.