Blood Pressure and Risk of Clinical Events in Peripheral Artery Disease

BackgroundCurrent guidelines recommend a blood pressure (BP) goal [&le;]130/80 mm Hg in peripheral artery disease (PAD) even though few PAD patients were enrolled in the landmark BP-lowering trials. Moreover, intensive BP control can worsen limb perfusion and none of the trials adjudicated limb events. MethodsUsing data from a longitudinal registry of US Veterans, we identified 91,296 patients (>2.7 million BP values) with a new diagnosis of PAD during 2015-2020. Multivariable Cox regression models evaluated the association between longitudinal BP values (time-varying exposure) and risk of cardiovascular (CV: myocardial infarction, stroke) and limb (chronic limb threatening ischemia, major amputation) events. ResultsMean age was 70.5 years, 97.3% were men and 18.5% were Black race. At baseline, the mean (SD) systolic BP was 133 (19) mm Hg and diastolic BP was 73 (11) mm Hg. Over a median 4.1 years, the incidence of CV and limb events was 4.6 per-100 patient-years and 5.0 per 100-patient-years, respectively. In adjusted Cox models, systolic BP [&ge;]140 mm Hg was strongly associated with higher risk of CV events with increasing risk across BP categories (130-139 mm Hg [reference]; 140-149 mm Hg: hazard ratio [HR]: 1.28 [95%CI: 1.16-1.41]; 150-159 mm Hg: HR 1.54 [1.39-1.72]; >160 mm Hg: 2.22 [2.02-2.44]). However, there was no association between systolic BP below 130 mm Hg and risk of CV events. In contrast, the association between systolic BP and limb events was U-shaped with the highest hazard of limb events at both low (<110 mm Hg: HR: 1.61 [1.48-1.74]) and high ([&ge;]160 mm Hg: HR: 1.53 [1.41-1.67]) systolic BPs. This discordance between CV and limb events, especially at lower BP was more pronounced in those with diabetes and severe PAD. Similar findings were seen in the analysis of diastolic BP with CV and limb events. ConclusionCurrent recommendations for BP goal in PAD patients are associated with optimizing risk of CV events but associated with a higher risk of limb events. Our findings highlight the need to better define BP goals for PAD patients, especially those at an increased risk of limb events.