The muddy waters of the J-curve and coronary revascularization

Do recent meta-analyses truly prove that treatment with blood pressure-lowering drugs is beneficial at any blood pressure value, no matter how low? A critical review

Current European guidelines for the management of hypertension and on cardiovascular disease prevention place the threshold for pharmacological treatment at a SBP level of 140 mmHg or above, with the exception of patients at very high risk (mainly because of coronary heart disease). This is in agreement with the current definition of hypertension, that is, the level of blood pressure at which the benefits of treatment outweigh the risks of treatment, as documented by clinical trials. This rationale and definition was recently challenged by meta-analyses using individual participant-level data from 48 randomized trials by the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC). The authors calculated for a fixed 5 mmHg pharmacological reduction of SBP an overall 10% risk reduction for major cardiovascular events. It was concluded that there was no reliable evidence of heterogeneity of treatment effects by baseline SBP categories; that the effect was independent from the presence of cardiovascular disease; applied also to old and very old individuals up to 84 years or beyond; and that BP-lowering was also beneficial in individuals with normal or high-normal SBP down to a baseline SBP less than 120 mmHg. In this report, we identify and discuss a number of shortcomings of the BPLTTC meta-analyses. In our view, the conclusions by the BPLTTC must be - together with accompanying suggestions to abandon the definition of hypertension - strongly rejected as they are not justified and may be harmful for cardiovascular health in individuals without hypertension.

Establishing target systolic and diastolic blood pressure in diabetic patients with hypertension: what do we need to consider?

INTRODUCTION

The optimum target for systolic and diastolic blood pressure remains divisive. In particular, the conflicting outcomes of the SPRINT and ACCORD trials have led to a divergence of guideline-recommended blood pressure targets for adults with diabetes.

AREAS COVERED

Here, we review the existing recommendations for blood pressure targets in diabetes, discussing the evidence base behind them and their limitations. We start by outlining the risks and benefits of lower systolic blood pressure targets among diabetics. We then follow with a separate appraisal of diastolic blood pressure targets, which necessitates examination of the 'J curve' and isolated diastolic hypertension.

EXPERT OPINION

Current and emerging evidence supports, on balance, a blood pressure therapeutic target of < 130/90 mmHg in adults at increased risk for cardiovascular disease, including diabetics. Whether certain diabetics with systolic BPs of 120-130 and/or diastolic BPs 80-90 mmHg require drug treatment to a target of <120/80 mmHg is less clear and requires more research.