Stress cardiovascular MR in routine clinical practice: referral patterns, accuracy, tolerance, safety and incidental findings

Abstract

Objective: The use of stress cardiovascular MR (CMR) to evaluate myocardial ischaemia has increased significantly over recent years. We aimed to assess the indications, incidental findings, tolerance, safety and accuracy of stress CMR in routine clinical practice.

Methods: We retrospectively examined all stress CMR studies performed at our tertiary referral centre over a 20-month period. Patients were scanned at 1.5 T, using a standardised protocol with routine imaging for late gadolinium enhancement. Angiograms of patients were assessed by an interventional cardiologist blinded to the CMR data.

Results: 654 patients were scanned (mean age 65±29 years; 63 inpatients; 9.6%). 14% of patients had incidental extracardiac findings, the commonest being liver or renal cysts (6%) and pulmonary nodules (4%). 639 patients (97.7%) received intravenous adenosine, 10 received intravenous dobutamine and 5 patients had both. Of the 15 patients who received dobutamine, 12 had no side-effects/complications, 2 experienced nausea and 1 chest tightness. Of the 644 patients who received adenosine, 43% experienced minor symptoms, 1% had transient heart block and 0.2% had severe bronchospasm requiring termination of infusion. There were no cases of hospitalisation or myocardial infarction. 241 patients also had coronary angiography. For detecting at least moderate stenosis of ≥50%, sensitivity was 86%, specificity 98% and accuracy 89%. For detecting severe stenoses of ≥70%, sensitivity was 91%, specificity 86% and overall accuracy 90%. These results compare very favourably with previous smaller research studies and meta-analyses.

Conclusion: We conclude that stress CMR, with adenosine as the main stress agent, is well tolerated, safe and accurate in routine clinical practice.

Figures

Figure 1

Receiver operating characteristic curve analysis for detection of moderate coronary artery stenoses of ≥50%. The area under the curve is 0.93±0.16.

Figure 2

Receiver operating characteristic curve analysis for detection of severe coronary artery stenoses of ≥70%. The area under the curve is 0.91±0.02.

Figure 3

(a) Stress-induced perfusion defect in the inferoseptal and inferior walls on first-pass perfusion imaging (arrows). (b) Correlating severe right coronary artery stenosis on coronary angiography (arrow). (c) Global subendocardial perfusion defects in a patient with severe triple-vessel coronary disease (stress perfusion image on the left, and comparative rest perfusion image on the right). (d) Late gadolinium enhancement image showing transmural infarction (non-viable myocardium) in the territory of the left anterior descending artery (black arrows), and an associated apical thrombus (white arrow) in the left ventricle.