Abstract 196: Quantitative Myocardial Perfusion Reserve Measured From Adenosine Stress Magnetic Resonance Imaging is Reduced in Women With Ischemia and Open Arteries Compared to a Normal Control Population
Background: Previous studies have demonstrated microvascular coronary dysfunction (MCD) in women with ischemia and open coronary arteries. We now examine whether this syndrome is also associated with compromised myocardial perfusion reserve as determined by adenosine stress/rest cardiac magnetic resonance imaging (CMRI).
Methods: CMRI was performed in 16 female patients (pts) with MCD and 12 control subjects (CON) matched by sex, age and BMI. All pts had MCD confirmed by abnormal coronary reactivity testing by catheterization and symptomatic myocardial ischemia with open arteries. CMRI at 1.5T used 0.05mmol/kg gadolinium for three slice stress followed by rest perfusion imaging. Myocardial perfusion reserve (MPR) was calculated as the ratio of stress/rest perfusion upslope, corrected for peak rate pressure product and left ventricular cavity input (MPR Index: MPRI), using PIE medical software. Data analysis used a standard two sample t-test and significance at p<0.05.
Results: CON were asymptomatic and had negative Bruce protocol ETT. There was no group differences in age (53.2±5.7 vs. 58.1±8.0 yrs, p=0.08) or BMI (25.9±3.1 vs. 25±3.4, p=0.48), but rate pressure product differed (12602±1523 versus 15684±2862, p=0.0023). MPRI was reduced in patients compared to controls (0.88±0.39 vs 1.21±0.35, respectively, p=0.02).
Conclusion: In women with abnormal coronary reactivity testing, ischemia and open arteries, CMR quantitatively demonstrates lower myocardial perfusion reserve compared to a control population.