Aggressive Blood Pressure Lowering Is Dangerous: The J-Curve

Abstract

Blood pressure (BP) is poorly controlled in the population, a phenomenon with adverse prognostic impact.1 However, a more aggressive approach toward BP lowering has been tempered over the last 2 to 3 decades by some reports suggesting a paradoxical increase in morbidity and mortality associated with an excessive reduction in BP, the so-called J-shaped curve hypothesis. Many investigations addressed this issue, and some excellent reviews discussed strengths and limitations of these studies in detail.2–5 We conducted an updated critical review of the most relevant studies and meta-analysis from our and other groups. We recognize that there is some evidence that a diastolic BP target <80 mm Hg,6 or an achieved diastolic BP <70 mm Hg,7 might be associated with an increased risk of myocardial infarction6 (MI) or total cardiovascular events7 in hypertensive patients with established coronary artery disease (CAD). However, with the possible exception of hypertensive patients with CAD, there are no convincing data behind the conclusion that an aggressive reduction of BP could be a direct cause of adverse outcome. Several studies that reported a J-shaped association between achieved BP and outcome have methodological limitations.2–5 In particular, several clinical conditions including, but not limited to, heart failure, previous MI, and cancer might have been the dominant and direct cause of adverse outcome in these patients, antihypertensive treatment being thus a sort of innocent bystander. As an implication of this line of thinking, dangerous would not be the excessive reduction in BP but rather the excessively low BP. The difference is not trivial. In subjects with or without risk factors, but free from overt cardiovascular disease, the log-linear relation between BP and rate of mortality from CAD or stroke appears to begin at values around 115/75 mm Hg, without …