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Articles by T Steedman
Total Records ( 2 ) for T Steedman
  S Watkins , R McGeoch , J Lyne , T Steedman , R Good , M. J McLaughlin , T Cunningham , V Bezlyak , I Ford , H. J Dargie and K. G. Oldroyd
 

Background— Magnetic resonance myocardial perfusion imaging (MRMPI) has a number of advantages over the other noninvasive tests used to detect reversible myocardial ischemia. The majority of previous studies have generally used quantitative coronary angiography as the gold standard to assess the accuracy of MRMPI; however, only an approximate relationship exists between stenosis severity and functional significance. Pressure wire–derived fractional flow reserve (FFR) values <0.75 correlate closely with objective evidence of reversible ischemia. Accordingly, we have compared MRMPI with FFR.

Methods and Results— One hundred three patients referred for investigation of suspected angina underwent MRMPI with a 1.5-T scanner. The stress agent was intravenous adenosine (140 µg · kg–1 · min–1), and the first-pass bolus contained 0.1 mmol/kg gadolinium. In the following week, coronary angiography with pressure wire studies was performed. FFR was recorded in all patent major epicardial coronary arteries, with a value <0.75 denoting significant stenosis. MRMPI scans, analyzed by 2 blinded observers, identified perfusion defects in 121 of 300 coronary artery segments (40%), of which 110 had an FFR <0.75. We also found that 168 of 179 normally perfused segments had an FFR ≥0.75. The sensitivity and specificity of MRMPI for the detection of functionally significant coronary heart disease were 91% and 94%, respectively, with positive and negative predictive values of 91% and 94%.

Conclusion— MRMPI can detect functionally significant coronary heart disease with excellent sensitivity, specificity, and positive and negative predictive values compared with FFR.

  R. A. P Weir , C. A Murphy , C. J Petrie , T. N Martin , S Balmain , S Clements , T Steedman , G. S Wagner , H. J Dargie and J. J. V. McMurray
  Background—

Microvascular obstruction (MO) is associated with large acute myocardial infarction and lower left ventricular (LV) ejection fraction and predicts greater remodeling, but whether this effect is abolished by contemporary antiremodeling therapies is subject to debate. We examined the influence of several infarct characteristics, including MO, on LV remodeling in an optimally treated post–acute myocardial infarction cohort, using contrast-enhanced cardiac magnetic resonance.

Methods and Results—

One hundred patients (mean age, 58.9±12 years, 77%men) underwent contrast-enhanced cardiac magnetic resonance at baseline (4 days) and at 12 and 24 weeks. The effects on LV remodeling (ie, change in LV end-systolic volume index [LVESVi]) of infarct site, transmurality, endocardial extent, and the presence of early and late MO were analyzed. Mean baseline infarct volume index decreased from 34.0 (21.2) mL/m2 to 20.9 (12.9) mL/m2 at 24 weeks (P<0.001). Infarct site had no influence on remodeling, but greater baseline infarct transmurality (r=0.47, P<0.001) and endocardial extent (r=0.26, P<0.01) were associated with higher LVESVi. Early MO was seen in 69 patients (69%) and persisted as late MO in 56 patients (56%). Patients with late MO underwent significantly greater remodeling than those without MO (LVESVi, +4.1 [13.4] versus –7.0 [12.7] mL/m2, respectively, P=0.001); those with early MO only displayed an intermediate LVESVi (–4.9 [13.0] mL/m2). Importantly, late MO was seen frequently despite optimal coronary blood flow having been restored at angiography.

Conclusions—

Late MO on predischarge contrast-enhanced cardiac magnetic resonance remains an ominous predictor of adverse LV remodeling despite powerful antiremodeling therapy and may be useful in the risk stratification of survivors of acute myocardial infarction.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00132093.

 
 
 
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