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Arterial Hypertension Health Article

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Prognosis

One of the most important prognostic factors in hypertension is electrocardiographic or echocardiographic LVH, with the latter already present in as many as 25% of patients with newly diagnosed hypertension. In a multicenter observational study of hypertensive patients with no prior history of cardiovascular or renal disease, echocardiographic LVH at baseline was accompanied by a 3-fold increase in the cumulative 4-year incidence of cardiovascular events (Fig. 63-9).

Because of the firmly established prognostic significance of LVH, numerous studies have examined the ability of antihypertensive therapy to cause regression of LVH. Meta-analyses, mostly of trials of monotherapy, estimate that left ventricular mass can be reduced by 11 to 12% with an ACE inhibitor or a CCB, by 8% with a thiazide diuretic, and by only 5% with a β-blocker. In contrast, in patients undergoing valve replacement for aortic stenosis, near-complete surgical normalization of systolic load results in a rapid and dramatic 35% reduction in left ventricular mass. The comparatively disappointing effects of the antihypertensive drug trials are likely related to the incomplete normalization of systolic load with monotherapy, and there is no evidence that differentiated effects on LVH should be the dominant determinant in the choice among antihypertensive medications.

Randomized controlled trials have provided unequivocal evidence that intensive lowering of blood pressure with combination therapy greatly reduces the risks of fatal and nonfatal cardiovascular events associated with untreated or inadequately treated hypertension. Until further evidence is provided, most of the cardiovascular benefit is explained by lowering the blood pressure per se rather than by the specific types of antihypertensive medication selected ¹⁰ (Fig. 63-10).

Despite the impressive body of randomized clinical trial data, it remains to be determined whether even intensive antihypertensive therapy can completely normalize the excessive risks of cardiovascular and renal disease associated with untreated hypertension. In a large hypertensive referral clinic in Gothenburg, Sweden, treating hypertension in initially middle-aged men to a goal of 160/90 to 95 mm Hg with diuretics and β-blockers for 20 years did not completely normalize the risk of myocardial infarction. The persistently elevated risks in the treated patients were related to the existence of associated risk factors, such as cigarette smoking and elevated blood lipids, and emphasize the need for global risk reduction and more intensive reductions in blood pressure. Randomized trials have not yet established whether even lower blood pressure goals than those presently endorsed would produce further reductions in cardiovascular morbidity and mortality and in the risk of end stage renal disease. Because of their relatively short duration (typically <5 years), randomized trials probably underestimate the protection against premature disability and death afforded by long-term antihypertensive therapy in clinical practice. In the Framingham Heart Study, treating hypertension for 20 years in middle-aged adults reduced total cardiovascular mortality by 60%, which is considerably greater than the results of most randomized trials despite the less intense treatment guidelines when therapy was initiated in the 1950s–1970s.

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