Cerebrovascular Control After Cardiac Rehabilitation in Ischemic Heart Disease Patients

Abstract

In this study we evaluate the impact of ischemic heart disease (IHD) and cardiac rehabilitation (CR) on cerebrovascular control and peripheral vascular health. Patients with IHD are at greater risk for stroke, a risk determined in part by cerebrovasoreactivity tests (i.e., dilation or constriction to a known stimulus). Exercise provides cerebrovascular health benefits in the aging population; yet, effects of IHD and CR (exercise) on cerebrovascular health indicators and cerebral blood flow control are not understood. We explored cerebrovascular control (i.e., vasoreactivity and autoregulation), peripheral vascular health, brain volume, and white matter hyperintensities (WMH) in a group of healthy adults (CTL), and patients with IHD after cardiac event (pre‐CR) and following 6 months CR (post‐CR) comprised of 2–3 sessions/week of 30 minutes moderate intensity aerobic exercise and 30 minutes of resistance training. In 23 participants (CTL: 11, IHD: 12; age range: 40–75 years), we measured changes in cross‐sectional area (ΔCSA) divided by changes in end‐tidal CO2 (ΔPetCO2: CTL: 2.3±1.2, pre‐CR: 4.1±3.2, post‐CR: 5.2±2.2 mmHg)] during hypercapnic (5% CO2, 95% oxygen; ADInstruments) conditions using a 3 Tesla (Siemens) scanner and T1‐weighted pulse sequence (0.7 mm isotropic). Vasoreactivity was calculated for the basilar (BA), left (L) and right (R) internal carotid (ICA), anterior (ACA), middle (MCA), and posterior cerebral arteries (PCA) using OsiriX software. Autoregulation of the MCA was assessed by measuring relative changes in MCA flow velocity with respect to changes in mean arterial pressure during a sit‐to‐stand task, quantified by rate of regulation (ROR). Peripheral vascular health metrics included brachial artery flow‐mediated dilation (FMD; %) and common carotid artery (CCA) intima media thickness (mm) using duplex ultrasound. Compared to CTL, those with IHD had lower CSA reactivity (mm/mmHg; mean±SD; p<0.05) in the BA (CTL: 0.74±0.73, pre‐CR: 0.29±0.29, post‐CR: 0.14±0.24), LICA (CTL: 1.1±0.86, pre‐CR: 0.93±1.03, post‐CR: 0.42±0.51), RICA (CTL: 0.93±0.71, pre‐CR: 0.48±0.35, post‐CR: 0.27±0.34), LMCA (CTL: 0.67±0.53, pre‐CR: 0.37±0.48, post‐CR: 0.14±0.12), and RMCA (CTL: 0.93±0.95, pre‐CR: 0.33±0.37, post‐CR: 0.29±0.33), which were not improved with CR. Compared to CTL, those with IHD had greater CCA IMT (CTL: 0.43±0.05, pre‐CR: 0.58±0.09, post‐CR: 0.59±0.07) which was not improved with CR, as well as lower ROR (CTL: 0.18±0.02, pre‐CR: 0.14±0.03, post‐CR: 0.16±0.03) and lower FMD (CTL: 9.1±4.3, pre‐CR: 4.7±2.3, post‐CR: 6.1±1.3; p<0.05) which were improved with CR. Finally, brain volume and white matter lesions were similar across groups. Therefore, compared to healthy individuals, the IHD patients exhibited impaired cerebrovascular control and peripheral endothelial function. Peripheral vascular health, and cerebrovascular autoregulation, were improved with 6 months of CR in these IHD patients.Support or Funding InformationCanadian Institute of Health Research (201503MOP‐342412‐MOV‐CEEA).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.