Elderly hypertensive patients who had coronary artery disease and a baseline systolic blood pressure greater than 150 mm Hg had significantly fewer cardiovascular deaths and strokes if they achieved a systolic pressure of less than 140 mm Hg, compared with similar patients who achieved a systolic pressure of 140-149 mm Hg.
The findings were noted in a post-hoc analysis of data collected from more than 8,000 patients in an international treatment study. The researchers compared outcomes for patients who achieved these two different levels of systolic pressure as a way to assess the new hypertension treatment goal of a systolic pressure less than 150 mm Hg in patients aged 60 years or older as recommended by the group originally appointed as the Eighth Joint National Committee (JNC 8) (JAMA 2014;311:507-20). Their finding that the patients who achieved the lower systolic pressure level of less than 140 mm Hg had a significantly lower rate of cardiovascular death and stroke as compared with patients whose systolic pressure remained in the 140-149 mm Hg range provided "important information to focus the risk-benefit discussion for patients who had on-treatment blood pressure in the 140-150 mm Hg range," wrote Dr. Sripal Bangalore, a cardiologist at New York University and his associates in an article published online on August 18 (J. Amer. Coll. Cardiol. 2014;311:784-93).
Dr. Sripal Bangalore
At least one expert questioned the ability of such a post-hoc analysis to address blood pressure goals in a meaningful way. "To adjudicate between a target of 140 mm Hg and 150 mm Hg it would be necessary to perform a prospective trial in which the population was randomized to these targets," commented Dr. Alan H. Gradman in an editorial that accompanied the new study (J. Amer. Coll. Cardiol. 2014;311:794-6). More aggressive blood pressure lowering could result in increased adverse events, he warned.
Despite these limitations, other experts hailed the new finding as important evidence against the recommendations of the former JNC 8 committee. "This study supports the concerns raised by many stakeholders, including the American College of Cardiology [ACC], the American Heart Association [AHA], and a number of the individual members of the JNC 8 panel (Ann. Intern. Med. 2014;160:499-503.), about the panel’s 2013 recommendations to raise blood pressure targets in older patients," said Dr. Patrick T. O’Gara, ACC president, and Dr. Elliott Antman, AHA president, in a joint written statement released to coincide with the new report’s publication.
"This new research suggests that raising the threshold for treatment of hypertension in patients 60 years of age or older with coronary artery disease may be detrimental to the best interest of patients and the public. It underscores ongoing concerns about adopting the unofficial 2013 targets as proposed by the panel originally appointed to write JNC 8," Dr. O’Gara and Dr. Antman said in their statement. Their statement added that "the ACC and AHA, working with the NHLBI [National Heart, Lung, and Blood Institute] are in the process of assembling the writing panel that will evaluate evidence from a variety of sources and provide a comprehensive update of the hypertension guideline."
The post-hoc analysis focused on a subgroup of 8,354 patients from among the 22,576 total patients enrolled in the (International Verapamil SR Trandolapril Study (INVEST), which enrolled patients aged 50 years or older with hypertension and pre-existing coronary artery disease at 862 centers in 14 countries (JAMA 2003;290:2805-16). Patients had been randomized to receive treatment with either a combination of verapamil sustained release plus trandolapril and hydrochlorothiazide if needed, or a combination of atenolol plus hydrochlorothiazide and trandolapril if needed, with a goal blood pressure on treatment of less than 140/90 mm Hg or less than 130/85 mmHg in patients with diabetes, renal impairment, or both. The primary, combined outcome of INVEST showed no significant difference in efficacy or safety between the two regimens compared in the study, and roughly 70% of patients in both treatment subgroups reached their goal blood pressures.
The new analysis selected the 8,354 patients who enrolled in INVEST at age 60 years or older and had a systolic blood pressure of at least 150 mm Hg at baseline. This subgroup included 4,787 patients (57%) who achieved a systolic pressure of less than 140 mm Hg after 24 months on study treatment, 1,747 patients who achieved a systolic pressure of 140-149 mm Hg after 24 months, and 1,820 patients whose systolic pressure failed to fall below 150 mm Hg.
In multiple propensity score – adjusted analyses, the rate of cardiovascular death was a relative 34% higher among patients with an achieved systolic pressure of 140-149 mm Hg, compared with those whose pressures fell below 140 mm Hg. Also, the total rate of stroke was 89% higher among patients whose pressures stayed in the 140-149 mm Hg range, compared with patients who achieved lower pressures. The rate of nonfatal stroke was 70% higher among the 140-149 mm Hg subgroup. All three of these differences were statistically significant.