Relation between blood pressure and vascular events and mortality in patients with manifest vascular disease: J-curve revisited

Abstract

Recent studies have challenged the notion that "lower is better" for blood pressure in relation to vascular events and mortality in patients with vascular disease, whereas practice guidelines currently recommend to lower blood pressure to <130/80 mm Hg. We reassessed this J-curved relationship between blood pressure and cardiovascular events and all-cause mortality in patients with various manifestations of vascular disease. For this purpose, 5788 patients with symptomatic vascular disease enrolled in the Secondary Manifestations of Arterial Disease Study were followed-up for the occurrence of new vascular events (ie, myocardial infarction, stroke, or vascular death) and all-cause mortality. During a median of 5.0 years (interquartile range: 2.6-8.1 years), 788 patients experienced a new vascular event, and 779 died. Overall, the covariate-adjusted relationship between mean baseline systolic, diastolic, or pulse pressure and the occurrence of vascular events followed a J-curve with increased event rates above and below the nadir blood pressure of 143/82 mm Hg. A similar nonlinear relationship was found for diastolic pressure and all-cause mortality. Elevated blood pressure was not associated with increased morbidity and mortality in patients with recently diagnosed coronary artery disease, ≥65 years, and having >60 mm Hg pulse pressure. Importantly, especially in these subgroups, low blood pressure could also be a symptom rather than a cause of disease. Blood pressure level below and above 143/82 mm Hg is, thus, an independent risk factor for recurrent events in patients with manifest vascular disease. Uncertainty of whether this association is causal provides a strong rationale for trials evaluating blood pressure treatment targets.