A study by investigators at Royal North Shore Hospital, Sydney, is the first to document persistent hypertension and vascular stiffness in cocaine users long after the acute effects have worn off. Previous studies have shown the immediate effects of cocaine on the heart, and primarily among cocaine addicts, not social users.
They enrolled 20 regular cocaine users and 20 non-users, both similar in age, gender, and self-reported history of dyslipidemia, diabetes, and hypertension. According to the researchers, cocaine use was the most significant predictor of systolic blood pressure (SBP) in regression analyses. No significant difference existed between the groups for diastolic blood pressure or heart rate.
Cocaine use compared with non-users was associated with reduced compliance (1.33 vs 1.69 mm2/mmHg, P
=0.004) and distensibility (3.76 vs 5.08 mmHg-1x10-3, P
=0.001) of the proximal descending aorta, and increased stiffness index (2.62 vs 2.07, P
=0.005) and pulse wave velocity (16.66 vs 14.42 m.s-1, P
=0.001). Cocaine use and age were the significant predictors of aortic stiffness. Cocaine users had an 18% greater left ventricular mass (LVM) than control subjects (P=
0.007), a difference that remained significant after indexing for BSA (P
=0.038). Cocaine use was the most significant predictor of LVM, independent of BSA and other covariates (β=-0.377, P=0.016). Regarding CMR diastolic function parameters, left atrial size was significantly larger in the user group compared to non-users (3.8cm vs 3.5cm, P=
0.041), however the difference was not significant when indexed for BSA.
"Regular cocaine use in otherwise healthy subjects is associated with increased SBP and aortic vascular stiffness, a significantly greater LVM independent of BSA or BP, and no evidence of previous MI," the Australian researchers concluded.