Relationship of delayed enhancement by magnetic resonance to myocardial perfusion by positron emission tomography in hypertrophic cardiomyopathy

Circ Cardiovasc Imaging. 2013 Mar 1;6(2):210-7. doi: 10.1161/CIRCIMAGING.112.000110. Epub 2013 Feb 15.

Abstract

Background: Presence of delayed enhancement (DE) on cardiac magnetic resonance (CMR) is associated with worse clinical outcomes in hypertrophic cardiomyopathy. We investigated the relationship between DE on CMR and myocardial ischemia in hypertrophic cardiomyopathy.

Methods and results: Hypertrophic cardiomyopathy patients (n=47) underwent CMR for assessment of DE and vasodilator stress ammonia positron emission tomography to quantify myocardial blood flow and coronary flow reserve. The summed difference score for regional myocardial perfusion was also assessed. Patients in the DE group (n=35) had greater left ventricular wall thickness (2.09±0.44 versus 1.78±0.34 cm; P=0.03). Stress myocardial blood flow (2.25±0.46 versus 1.78±0.43 mL/min per gram; P=0.01) and coronary flow reserve (2.78±0.32 versus 2.01±0.52; P<0.001) were significantly lower in DE-positive patients. Summed difference score (7.3±6.6 versus 0.9±1.4; P<0.0001) was significantly higher in patients with DE. A coronary flow reserve <2.00 was seen in 18 patients (51%) with DE but in none of the DE-negative patients (P<0.0001). CMR and positron emission tomography showed visually concordant DE and regional myocardial perfusion abnormalities in 31 patients and absence of DE and perfusion defects in 9 patients. Four DE-positive patients demonstrated normal regional myocardial perfusion, and 3 DE-negative patients had (apical) regional myocardial perfusion abnormalities.

Conclusions: We found a close relationship between DE by CMR and microvascular function in most of the patients studied. However, a small proportion of patients had DE in the absence of perfusion abnormalities, suggesting that microvascular dysfunction and ischemia are not the sole causes of DE in hypertrophic cardiomyopathy patients.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Cardiomyopathy, Hypertrophic / diagnosis*
  • Cardiomyopathy, Hypertrophic / diagnostic imaging
  • Cardiomyopathy, Hypertrophic / physiopathology
  • Chi-Square Distribution
  • Coronary Circulation*
  • Cross-Sectional Studies
  • Female
  • Fractional Flow Reserve, Myocardial
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Microcirculation
  • Middle Aged
  • Myocardial Ischemia / diagnosis*
  • Myocardial Ischemia / diagnostic imaging
  • Myocardial Ischemia / physiopathology
  • Myocardial Perfusion Imaging / methods*
  • Positron-Emission Tomography*
  • Predictive Value of Tests
  • Prognosis
  • Vasodilator Agents

Substances

  • Vasodilator Agents