Dipyridamole stress and rest transmural myocardial perfusion ratio evaluation by 64 detector-row computed tomography

J Cardiovasc Comput Tomogr. 2011 Nov-Dec;5(6):443-8. doi: 10.1016/j.jcct.2011.10.012. Epub 2011 Nov 4.

Abstract

Background: Myocardial stress CT perfusion (CTP) can detect myocardial ischemia.

Objective: We evaluated the transmural perfusion ratio (TPR) of dipyridamole stress CTP to detect significant coronary stenosis (>70%) defined by quantitative invasive coronary angiography (ICA).

Methods: Twenty-six patients (61.6 ± 8.0 years old; 14 males), without prior myocardial infarction, with positive single-photon emission computed tomography (SPECT; <2 months) and clinical indication for ICA, underwent a customized multidetector-row CT (MDCT) protocol with rest/stress myocardial perfusion evaluation and coronary CT angiography. TPR was defined as mean subendocardial divided by mean subepicardial attenuation and quantified on rest and stress MDCT images. Abnormal TPR was defined as 2 SDs below the mean rest TPR.

Results: All 26 patients completed the CT protocol with no adverse events. Rest TPR was measured in all patients with a mean of 1.06 ± 0.11, and abnormal TPR was considered <0.85. For 6 patients with normal coronary arteries by ICA, the mean TPR of territories with a previous positive perfusion defect in SPECT was 1.02 ± 0.18 (95% CI, 0.86-1.18; n = 6), and mean TPR of territories without perfusion defect in SPECT was 1.03 ± 0.09 (95% CI, -0.95 to 1.11; n = 12; P = 0.83). Mean stress TPR in territories with positive SPECT and significant coronary artery disease by quantitative ICA was 0.71 ± 0.13 (95% CI, -0.64 to 0.77) and in the remote myocardial was 1.01 ± 0.09 (95% CI, -0.96 to 1.06; P < 0001). In these territories, a significant Pearson's correlation was observed (r = -0.74, P < 0.001).

Conclusion: TPR has a good correlation with SPECT and ICA to detect significant coronary stenosis.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Aged
  • Brazil
  • Coronary Angiography
  • Coronary Circulation*
  • Coronary Stenosis / diagnostic imaging*
  • Coronary Stenosis / physiopathology
  • Dipyridamole*
  • Female
  • Hemodynamics
  • Humans
  • Male
  • Middle Aged
  • Myocardial Perfusion Imaging / methods*
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Severity of Illness Index
  • Tomography, Emission-Computed, Single-Photon
  • Tomography, X-Ray Computed*
  • Vasodilator Agents*

Substances

  • Vasodilator Agents
  • Dipyridamole