Reduced reactive hyperemia in HIV-infected patients

Given that several pathology-based studies reported some degree of coronary and arterial vasculopathy in HIV-infected patients, we investigated whether abnormal vascular reactivity may also be found in these patients.

Vascular reactivity was assessed noninvasively using finger-skin blood-flow monitoring by laser-Doppler flow measurement in 10 HIV-infected-patients (mean CD4 T-cell count, 350+/-84 cells/mm3) with cardiac symptoms (previous myocardial infarction or left-ventricular dysfunction) and/or HIV-related protease inhibitor-induced hyperlipemia (group 1, symptomatic), 19 HIV-infected patients free of cardiac disease, hyperlipemia, and previous opportunistic infections (mean CD4 T-cell count, 333+/-175 cells/mm3; group 2, asymptomatic), and 19 healthy control subjects (group 3). Laser-Doppler flow was measured at baseline, during postocclusive hyperemic response following transient interruption of brachial blood flow (reactive hyperemia), during transcutaneous delivery of acetylcholine (Ach) using iontophoresis (endothelium-dependent dilation) and after sublingual nitroglycerin administration (endothelium-independent dilation).

During reactive hyperemia, the absolute increase in flow was found to be lower in asymptomatic HIV-infected patients than in controls (median values [25th-75th percentile]: asymptomatic: 300 [200-400]; versus controls: 600 [400-750] arbitrary units [AU]; p< or =.0001). This abnormality was more pronounced in symptomatic patients (100 [100-200]; p< or =.0001). There was also a reduced peak/baseline flow ratio (symptomatic: 1.14 [1.1-1.2]; asymptomatic: 1.40 [1.25-1.5]; versus controls: 1.83 [1.6-2.2]; p<.0001 for both comparisons) and a reduced hyperemic response, as assessed by the curve of area under the flow versus time from deflation to the end of the hyperemic response (symptomatic: 1850 [1100-2225]; asymptomatic: 6000 [2850-7950]; versus controls: 23,735 [16,000-31, 800] AU x sec; p<.0001 for both comparisons). Although there was no statistically significant difference in acetylcholine (Ach)-induced increases in flow between asymptomatic HIV patients and controls (peak/baseline flow ratio: 6 [4.4-10] versus 5.3 [4-8]; p =.47), a trend to lower values was seen in symptomatic patients (4.4 [1.2-5]; p =.06). Administration of 0.4 mg sublingual nitroglycerin resulted in increases in flow without statistically significant difference between patients and controls: peak/baseline flow ratio for symptomatic: 2.4 [1.9-2.7]; asymptomatic: 2.1 [1.75-2.34] versus controls: 1.97 [1.8-2.4]; p =.2 and.83, respectively).

Postischemic reactive hyperemia is reduced in HIV-infected patients. In addition, there was is trend for a reduced response to Ach only in those with cardiac disease and/or hyperlipemia.