Effect of Myocardial Perfusion Pattern on Frequency and Severity of Mitral Regurgitation in Patients With Known or Suspected Coronary Artery Disease

Abstract

Mitral regurgitation (MR) is common with coronary artery disease (CAD), as altered myocardial substrate can impact valve performance. SPECT myocardial perfusion imaging (MPI) enables assessment of myocardial perfusion alterations. This study examined perfusion pattern in relation to MR. 2377 consecutive patients with known or suspected CAD underwent stress MPI and echocardiography (echo) within 1.6±2.3 days. MR was present on echo in 34% of patients, among whom 13% had advanced (≥moderate) MR. MR prevalence was higher among patients with abnormal MPI (44% vs. 29%, p<0.001), corresponding to increased global ischemia (p<0.001). Regional perfusion varied in left ventricular (LV) segments adjacent to each papillary muscle: Adjacent to the anterolateral papillary muscle, magnitude of baseline and stress-induced anterior/anterolateral perfusion abnormalities was greater among patients with MR (both p<0.001). Adjacent to the posteromedial papillary muscle, baseline inferior/inferolateral perfusion abnormalities were greater with MR (p<0.001), whereas stress inducibility was similar (p=0.39). In multivariate analysis, stress-induced anterior/anterolateral and rest inferior/inferolateral perfusion abnormalities were independently associated with MR (both p<0.05) even after controlling for perfusion in reference segments not adjacent to the papillary muscles. MR severity increased in relation to magnitude of perfusion abnormalities in each territory adjacent to the papillary muscles, as evidenced by greater prevalence of advanced MR among patients with ≥moderate anterior/anterolateral stress perfusion abnormalities (10.7% vs. 3.6%), with similar results when MR was stratified based on rest inferior/inferolateral perfusion (10.4% vs. 3.0%, both p<0.001). In conclusion, findings demonstrate that myocardial perfusion pattern in LV segments adjacent to the papillary muscles influences presence and severity of MR.

Right Ventricular Dysfunction Impairs Effort Tolerance Independent of Left Ventricular Function Among Patients Undergoing Exercise Stress Myocardial Perfusion Imaging

“…Attenuation correction imaging and/or prone reposition imaging (as clinically tolerated) was used to differentiate between pathologic perfusion deficits and attenuation artifact in accordance with previously employed methods. 12, 15 Post-stress images were acquired approximately 30 minutes following exercise, and 1–2 hours following pharmacologic stress.…”

“…Regional LV perfusion was assessed using uniform partitions (see Figure 1), whereby LV was partitioned into three equal size (anterior, inferior and lateral) territories, in accordance with prior methods as employed by our group 15, 19 : Summed stress, rest, and difference scores in each territory were calculated as the sum of individual perfusion scores within encompassed segments. Perfusion territories were not mutually exclusive; patients with defects in multiple territories were scored for each territory based on extent and severity of constitutive segmental deficits.…”

Mitral valve disease—morphology and mechanisms

“…290,291 Patients whose IMR will improve with revascularization of ischaemic, but viable, subpapillary muscle myocardium alone 292 are being predicted using advanced cardiac perfusion imaging. 293 …”

Ischemic mitral regurgitation

“…Previously, they have looked at such features as delayed enhancement MRI to detect subclinical infarction of the papillary muscles. Their interest in perfusion as it relates to the presence of ischemic mitral regurgitation was elegantly demonstrated in their recent manuscript that clearly demonstrated that the myocardial perfusion pattern in left ventricular segments adjacent to the papillary muscles influenced both the presence and the severity of MR in a cohort of over 2000 patients [5]. In the current study, the authors extended their findings to explore the relationship between myocardial perfusion pattern and magnitude of mitral regurgitation in patients undergoing PCI.…”