Limitations in the current screening practice of assessing left ventricular ejection fraction for a primary prophylactic implantable defibrillator in southern Ontario

Screening patients for primary prophylaxis implantable cardioverter defibrillators: Insights into current practices

“…The highest agreement (91%) occurred in the group with severely depressed LVEF, followed by the group with normal LVEF. In patients with mild to moderate systolic dysfunction, the agreement between 2D echocardiography and RNA was less than 50%, similar to findings observed by Lane et al (4). Previous work by Yu et al (12) demonstrated that this correlation can be improved (r=0.95) with contrast echocardiography.…”

“…In this context, the study by Lane et al (4) in the present issue of The Canadian Journal of Cardiology is extremely welcomed. The authors conducted a 'real-world' prospective cohort study on screening practices for ICD implantation in southern Ontario.…”

“…Clinical trials that led to the guidelines for primary prevention ICD insertion used various techniques for LVEF assessment, including echocardiography and equilibrium radionuclide angiography (RNA), as used in the study by Lane et al (4). Given the results of these trials, the American College of Cardiology/American Heart Association/ Heart Rhythm Society (5) currently recommend that the clinician use the LVEF determination method believed to be the most clinically accurate and appropriate in their respective institution.…”

“…This may falsely exaggerate the measured inaccuracies. Finally, although less likely, the suitable imaging modality that best quantitates LV function and predicts risk may not be RNA as used in the analysis (4). A subanalysis of SCD-HeFT (24) illustrated that among the 2521 patients enrolled in SCD-HeFT, LVEF was measured by RNA in 616 (24%), echocardiography in 1469 (58%) and contrast angiography in 436 (17%).…”

“…In the future, evaluation of scar using magnetic resonance imaging or new radiotracers may become useful, but this will require validation in large populations. Therefore, based in part on data from Canadian centres (4,22), patients with known cardiomyopathy requiring LVEF evaluation for consideration of prophylactic ICD insertion may benefit from RNA assessment.…”