Hypertension-related organ damage and vascular disease

Abstract

Hypertension is a very common condition with an overall prevalence of 42% in the general population in the Netherlands, rising to a prevalence of 60-70% beyond the seventh decade of life. Usually, hypertension is asymptomatic, but as a risk factor attributes to approximately 2/3 of stroke and 1/2 of ischemic heart disease. Obesity leads to hypertension by various mechanisms, often referred to as obesity-related hypertension. We evaluated the prevalence and the vascular risk of the combination of obesity and hypertension in patients with vascular diseases. The prevalence of the combination of obesity and hypertension was low and patients with high blood pressure combined with a high weight were not at higher risk for vascular events or mortality as were patients with only high weight. Obesity is also related to cardiac left ventricular hypertrophy (LVH). Whether LVH criteria on ECG are a result of increased cardiac electrical activity, or due to increased left ventricular mass (LVM) remains to be determined. We investigated the relation between obesity and LVH criteria on ECG (ECG-LVH) and LVM by MRI (MRI-LVM) in patients with hypertension. Linear regression analysis revealed an inverse relation between waist and Sokolow-Lyon voltage and a positive relation between waist and MRI-LVM. Presence of LVH on ECG can be assessed with multiple criteria. We evaluated the vascular risk and all-cause mortality related to 4 ECG criteria for LVH in patients with vascular disease. The prevalence of the Sokolow-Lyon, Cornell voltage, Perugia and the LIFE criterion was 8%, 4%, 12% and 12%, respectively. The risk for vascular events and mortality was increased with presence of each LVH-criterion, but most notably with the Perugia criterion. Whether combined presence of hypertensive target organ damage confers higher vascular risk compared to single presence is unknown. We evaluated the separate and combined effects of impaired renal function, albuminuria and LVH on the occurrence of vascular events and mortality in patients with vascular disease. LVH was present in 11%, impaired renal function in 15% and albuminuria in 18%. The risk for vascular events had a HR of 1.5 (95%CI 1.2 to 1.9) for presence of 1 manifestation of hypertensive target organ damage and HR 3.8 (95%CI 2.3 to 6.3) for 3 manifestations. For mortality this was HR 1.4 (95%CI 1.1 to 1.7) and HR 3.2 (95%CI 1.9 to 5.2). We investigated the effect and cost-effectiveness of an internet-based, nurse-led vascular risk factor management program on vascular risk factors.Therefore we conducted a prospective multicentre randomized controlled trial. Patients were diagnosed with a recent vascular event and with ≥2 treatable risk factors not at goal. After 1 year we found a relative change of -14% (95%CI -25 to -2%) in Framingham Heart Risk score of the intervention group compared to the usual care group. The intervention yields both improvements in quality of live and less societal costs. The probability that the intervention is cost-effective at a threshold of €20,000 per QALY, was 66%. At annual cost of €155, the intervention was relatively cheap.