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.