Abstract 6203: Central Pulse Pressure ≥50 mmHg Predicts Adverse Cardiovascular Outcome: The Strong Heart Study
Central (aortic) and brachial blood pressure differ as a consequence of pulse wave amplification and wave reflection. Central pressure more closely reflects the load placed on the left ventricle and the coronary and cerebral vasculature. We previously documented that central pulse pressure (PP) better correlated with carotid hypertrophy and extent of atherosclerosis and better predicted incident cardiovascular disease (CVD) than did brachial PP in the Strong Heart Study (SHS). We sought to determine a threshold value of central PP that might predict adverse outcome and thereby provide a target for design of intervention strategies. Radial applanation tonometry was performed to noninvasively estimate central PP. Cox regression analyses were performed using pre-specified covariates (age, sex, body mass index, current smoking, total:HDL cholesterol ratio, diabetes status, creatinine, fibrinogen, and heart rate). To this basic model, quartiles of central and brachial PP were entered in separate models. Among the 2,405 SHS participants without prevalent CVD at the time of evaluation, 344 events occurred during 5.6± 1.7 years. Adverse cardiovascular events were predicted by quartiles of central (p<0.001) but not brachial PP (p=0.052). Event rates in the first to fourth quartile of central PP were 11.0%, 9.9%, 15.0%, and 21.3%. With adjustment for covariates, only the event rate in the fourth quartile (central PP ≥50 mmHg) was significantly higher than that in the first quartile (HR 1.69, 95% CI: 1.20–2.39, p=0.003). Central PP ≥50 mmHg was significantly related to outcome in both men (HR 2.06, 95% CI: 1.39–3.04, p<0.001) and women (HR 2.03, 95% CI: 1.55–2.65, p<0.001); in participants with diabetes (HR 1.84, 95% CI: 1.41–2.39, p<0.001) and without diabetes (HR 1.91, 95% CI: 1.29–2.83, p=0.001); and in individuals below (HR 2.51, 95% CI: 1.59–3.95, p<0.001) and above (HR 1.53, 95% CI: 1.19–1.97, p<0.001) the age of 60. Central PP ≥50 mmHg predicts adverse cardiovascular outcome, independent of other CVD risk factors. These findings support prospective examination of noninvasively-estimated central PP as a treatment target in intervention strategies and treatment trials.