SNOWMASS, COLO. – Be leery of lowering high blood pressure too much in patients with lower extremity peripheral artery disease, Robert A. Vogel, MD, cautioned the Annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology
“We used to worry about lowering blood pressure too much in [coronary artery disease]. I need to rekindle that thought, because you want to be very careful about lowering blood pressure too much in PAD,” said Dr. Vogel, a preventive cardiology specialist at the University of Colorado, Denver.
He cited a recent reanalysis of data from the landmark ALLHAT (Antihypertensive and Lipid-lowering Treatment to Prevent Heart Attack Trial) conducted by investigators at Stanford (Calif.) University. During a median 4.3 years of prospective follow-up of 33,357 participants with a median baseline blood pressure of 146/84 mm Hg, the risk of the composite endpoint of lower extremity PAD events – defined as PAD-related hospitalization, revascularization procedures, medical treatment, or PAD-related death – was increased by 26% in patients with a systolic blood pressure below 120 mm Hg, compared with an SBP of 120-129 mm Hg.
In a similar Cox regression analysis, the risk of PAD events was increased by 72% in patients with a diastolic blood pressure below 60 mm Hg, compared with that of patients with a DBP of 70-79 mm Hg, and to a lesser, albeit still statistically significant and clinically meaningful, extent in those with a DBP of 60-69 mm Hg (Circulation. 2018;138:1805-14).
Dr. Vogel’s cautionary note about overzealous blood pressure–lowering was one of several developments he highlighted since publication of the 2016 American Heart Association/American College of Cardiology guidelines on the medical management of lower extremity PAD (J Am Coll Cardiol. 2017;69:1465-508). Others include new data demonstrating that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor therapy shows particularly strong benefit in the patient subgroup with PAD, as did rivaroxaban (Xarelto) at 2.5 mg b.i.d. plus aspirin 100 mg/day in the COMPASS trial.
Also, the final week of 2018 saw publication of the ACC Expert Consensus Decision Pathway on Tobacco Cessation (J Am Coll Cardiol. 2018 Dec 25;72:3332-65), which Dr. Vogel considers an exemplary document every physician who cares for patients with PAD ought to read.
The Class I recommendations in the ACC/AHA guidelines for medical management of PAD include introducing a supervised exercise program before resorting to a revascularization procedure, providing advice on smoking cessation at every visit, antiplatelet therapy, a high-intensity statin, cilostazol for claudication, and coordination of the patient’s diabetes care with an endocrinologist or primary care physician.
Numerous studies have documented that physicians by and large aren’t doing so well in bringing these evidence-based therapies to bear. For example, a recent study of 155,647 Veterans Affairs patients with new-onset PAD found that 28% weren’t on a statin. Only 18.4% with PAD and comorbid coronary or carotid disease were on a high-intensity statin, as were just 6.4% with PAD only. In a multivariate adjusted analysis, high-intensity statin users had a 33% lower risk of amputation and a 26% lower risk of mortality, compared with statin nonusers (Circulation. 2018;137:1435-46).
It’s as if there’s a widespread failure to appreciate the substantial morbidity and mortality conferred by PAD, so Dr. Vogel put it into perspective: “In broad strokes, atherosclerosis starts in the aorta, moves to the coronaries, goes to the carotids, and ends up in the legs. By the time you have lower-extremity atherosclerosis, you are a vasculopath,” he explained.