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

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.

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.

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.

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