Is there a sweet spot for BP when treating hypertension?

When treating hypertensive patients, there may be a blood pressure (BP) goldilocks zone for best outcomes, results published Aug. 15 in the Journal of the American College of Cardiology suggest.

These findings contradict previous recommendations to aggressively lower BP to improve outcomes.

Hypertension, while improving with increased control, still affects more than a third of Americans. Many hypertensive patients are likewise burdened with comorbidities that complicate outcomes. Most comorbidities not only have a chicken-egg question for hypertension in patients, but also lead to a domino effect of outcomes.

The research team led by John J. Sim, MD, of the Kaiser Permanente Los Angeles Medical Center’s Division of Nephrology and Hypertension, assessed mortality and end-stage renal disease outcomes in a diverse group of treated hypertensive subjects as both a combined and separate endpoint.

Part of their findings may be obvious to some: the higher end of the range of blood pressures had a high risk of the combined endpoint of mortality and end-stage renal disease (hazard ratio 4.9, rate of 15.7 percent). However, the same was seen for those patients whose BP had been driven down to its lowest possible point (hazard ratio 4.1, rate of 22.9 percent). Instead, when looking at the combined endpoint, the best outcomes and lowest risks were seen in patients with a BP of 137/71 mmHg. 

Sim et al also found correlations with diabetes, BP, mortality and end-stage renal disease. Nondiabetics did better at higher BPs than diabetics did in general. For mortality alone, nondiabetics had a better survival rate at higher BP, while for end-stage renal disease outcomes, diabetics seemed to fare better than nondiabetics in the low BP range.

While mortality alone maintained a U-shaped risk graph, end-stage renal disease showed a J-shaped risk outcome. However, Sim et al suggested that the combined endpoint was more relevant as end-stage risk alone could be misleading.

In a sub-finding noted by the research team, the mean systolic and diastolic BP for those patients who died decreased during the 60 days before death. Systolic BP dropped approximately 7 mm Hg and diastolic blood pressure dropped by about 3 mm Hg.

Sim et al recommended getting patient BPs to within 10 points of nadir for both systolic and diastolic pressure. It is important to remember that these findings are relative to patients being treated for BP.

"We hope our findings will pave the way for a more effective strategy in treating high blood pressure," said Sim in a press release. "Through personalized treatment plans, we can minimize the lifestyle burden on patients and improve the safety of their treatment regimens, while reducing the cost to both patients and the healthcare system as a whole."

In an editorial response, Charlotte Andersson, MD, PhD, of Gentofte Hospital in Hellerup, Denmark, and colleagues wrote that this data would be more robust when analyzing against other comorbidities. “It may make sense to treat younger people with less comorbidity more aggressively than older patients or people with a large burden of comorbidity, but the exact numerical BP targets are yet to be determined.”

Still, Sim et al wrote that patients on either end of the mean were still at greater risk for poorer outcomes, particularly death and end-stage renal failure, and cautioned against extremes. “Whereas current U.S. guidelines emphasize the upper limits of therapeutic goals, the potential dangers of overtreatment may need to be considered.”