Early target organ damage and its reversibility: the heart

Left ventricular hypertrophy (LVH) represents not only an adaptation to increased load, but also a risk factor and a marker of risk of cardiovascular diseases. It may be detected early in the development of the disease by electrocardiography or echocardiography. LVH is often associated to abnormalities of systolic and diastolic function, and its presence clearly predisposes not only to cardiac ischemia and to congestive heart failure, but also to a higher incidence of stroke. A large number of clinical and experimental studies have shown that long-term antihypertensive treatment may be associated with regression of LVH. Long-term antihypertensive treatment is associated with a progressive decrease of LV mass. Differences on reduction of LV mass using different classes of antihypertensive drugs for the same decrease of blood pressure are usually mild, although the effect on cardiac structure and tissue composition are probably not the same. In fact, not only the quantity of left ventricular mass, but also its quality (i.e., collagen content, contractile machinery) should be evaluated and improved by treatment. The incidence of cardiovascular events in hypertensive patients is clearly related to the value of LV mass achieved during treatment; in fact, a reduction in LVH by antihypertensive treatment is associated with improvement in outcome and with decrease of the risk of cardiovascular morbidity and mortality, even independently from changes of other risk factors, including blood pressure. In patients with LVH at baseline, the decrease of LV mass is associated with a number of pathophysiological changes such as 1) improved systolic performance at the midwall, 2) possible improvement of diastolic filling, 3) autonomic nervous system changes toward normalization, 4) possible reduction or ventricular arrhythmias and 5) coronary reserve improvement. All these changes might explain an improvement of clinical prognosis in hypertensive patients. Ongoing studies will more precisely assess the quantitative relation between development or regression of LV mass, improvement of systolic and diastolic function and incidence of cardiovascular events. At present time detection, prevention and reversal of LVH represent a major goal in the management of hypertensive patients.