Risks lowest for BP less than 130/80 mmHg

Intensive blood pressure control may reduce the risk of cardiovascular events in adults with hypertension and left ventricular hypertrophy (LVH) as a new analysis reports that in these patients, risks for cardiovascular disease (CVD) were lowest for those with systolic blood pressures (SBPs) of 120-129 mmHg and diastolic blood pressures (DBPs) of 80-89 mmHg.

As reported by the SPRINT (Systolic Blood Pressure Intervention Trial) investigators, intensive treatment that aimed at lowering the systolic blood pressure target to less than 120 mmHg reduced stroke and other cardiovascular events when compared to a systolic target of less than 140 mmHg. As a result, guidelines were updated to recommend targeting pressures less than 130/80 mmHg for most patients.

But a number of recent studies suggest that “excessive BP lowering can also increase CVD events in high-risk patients or those with established CVD; consequently, the 2018 European Society of Cardiology/European Society of Hypertension guidelines incorporated a lower limit for BP control of 120/70 mm Hg,” wrote Hyeon Chang Kim, MD, PhD, of Yonsei University College of Medicine, Seoul, Korea, and fellow researchers in the Journal of the American College of Cardiology.

But much about optimal targets—including the appropriate “low threshold”—remains unsettled for a number of reasons. For example, analysis of the effects of intensive BP lowering in patients with LVH—a marker of cardiac end-organ damage—was not a focus in either the SPRINT or the ACCORD trial.

“Intensive BP lowering in patients with LVH can lead to the regression of myocardial hypertrophy and subsequently exert beneficial effects on CVD outcomes. On the contrary, because of the increased myocardial compressive pressure on coronary arteries and impaired left ventricular filling in LVH, excessive BP lowering might hinder adequate myocardial perfusion and elevate the risk of CVD events,” noted Kim et al.

Therefore, they sought to assess the possible association between on-treatment BP and cardiovascular outcomes in patients with hypertension and LVH. The primary outcome was comprised of a composite CVD event, which researchers defined as first hospitalization for myocardial infarction (MI), stroke, or heart failure (HF), or a CVD-related death. Secondary events consisted of MI, stroke, and hospitalization for HF.

Using data from a nationwide health examination database—the National Health Insurance Service that includes medical claim records from the entire population of South Korea—Kim and colleagues identified 95,545 participants (median age: 62 years; 63.6% male) being treated for hypertension who had LVH at baseline and followed them for a median of 11.5 years, during which 12,035 new CVD events occurred.

In all, 45.4% of participants had an SBP of ≥140 mmHg, 32.0% had SBPs of 130-139 mmHg, 18.0% had SBPs of 120-129 mmHg, and 4.6% had SBPs of <120 mmHg. In addition, 27.7% had a DBP of ≥90 mmHg, 48.8% had a DBP of 80-89 mmHg, 21.1% had a DBP of 70-79 mmHg, and 2.4% had a DBP of <70 mmHg.

In general, those with higher SBPs were older, but those with higher DBPs were younger.

The lowest risk for CVD events was associated with SBPs of less than 130 mmHg and DBPs of less than 80 mmHg. Upon multivariable-adjusted analysis using SBP of 120-129 mmHg as the reference, Kim and colleagues found that hazard ratios (HRs) were highest in participants with SBPs ≥140 mmHg (HR: 1.31; 95% CI: 1.24-1.38), followed by those in the 130-139 mmHg range (HR: 1.08; 95% CI: 1.02-115), and those in the <120 mmHg group (HR: 1.03; 95% CI: 0.93-1.15).

Results using DBPs of 70-79 mmHg as the reference were similar, with HRs of 1.30 (95% CI: 1.24-137) in patients with DBP of ≥90 mmHg and 1.06 (95% CI: 1.01-1.12) in those with 80-89 mmHg DBPs, but slightly higher in those with DBPs <70 mmHg (HR: 1.08; 95% CI: 0.96-1.20).

BP levels <120/70 mmHg, however, were not associated with additional CVD risk reductions.

“Despite decades of attention, the treatment of hypertension is suboptimal in both the United States and globally,” wrote S. Andrew McCullough, MD, of Weill Cornell Medicine, New York, New York; David C. Goff, JR, MD, PHD, of National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, and Peter M. Okin, MD, also of Weill Cornell Medicine, in an accompanying editorial comment.

“The findings from [Kim] et al provide real-world evidence that in high-risk patients with hypertension and LVH, achieving lower SBP and DBP is associated with an overall reduction in cardiovascular events. These data, though observational, are consistent with major randomized controlled trials that inform the American College of Cardiology/ American Heart Association, European Society of Cardiology, and International Society of Hypertension guidelines for the treatment and control of hypertension,” they added.

“Data from randomized trials and observational studies continue to support the notion that the control of hypertension globally will be crucially important in preventing cardiovascular events. Lee et al provide further evidence that in patients with hypertension who are on therapy, a large percentage of patients remain without optimal control; >75% of patients in their study had either SBP >130 mm Hg or DBP >80 mm Hg. Efforts should be made to address medication nonadherence and clinical inertia to treat to lower SBP goals, which are 2 principal drivers of poor control of hypertension,” conclude McCullough, Goff, and Okin.

Study limitations include its retrospective nature, possible residual confounding and bias, unvalidated status of the diagnostic accuracy of LVH, use of LVH criteria with high specificity in the Asian population, failure to assess LVH persistence throughout follow-up, the use of averaged BPs, and inclusion of only Korean adults with LVH.

  1. This study, which focuses on patients with hypertension and left ventricular hypertrophy (LVH), verifies the cardiovascular benefits of intensive blood pressure control seen in the SPRINT and ACCORD studies.

  2. In adults with hypertension and LVH, the risk for CVD events was lowest for systolic blood pressures (SBPs) <130 mmHg and diastolic blood pressures (DBPs) <80 mmHg.

Liz Meszaros, Deputy Managing Editor, BreakingMED™

This work was supported by the Korea Health Technology Research and Development Project through the Korea Health Industry Development Institute funded by the Ministry of Health and Welfare, Republic of Korea.

Kim reported no relationships relevant to the contents of this paper to disclose.

McCullough is a minority stakeholder in Moderna and Verve Therapeutics; Okin has received consulting honoraria from Bristol Myers Squibb, and Goff has reported that he has no relationships relevant to the contents of this paper to disclose.

Cat ID: 6

Topic ID: 74,6,730,6,192,916