Dynamic handgrip exercise for the detection of myocardial ischemia using fast Strain-ENCoded cardiovascular magnetic resonance.

Summary

In a prospective cohort of 260 high-risk patients, dynamic handgrip exercise combined with fast SENC CMR detected obstructive CAD with 79% sensitivity and 87% specificity versus pharmacologic stress CMR. In 105 patients with invasive angiography, sensitivity and specificity were 82% and 89%, respectively, while scan time was markedly shorter than conventional stress CMR protocols.

Key Findings

• Sensitivity 79% and specificity 87% versus pharmacologic stress CMR in 260 patients.
• In 105 patients with recent invasive coronary angiography, sensitivity 82% and specificity 89% for obstructive CAD.
• DHE-fSENC exam time was significantly shorter than adenosine-perfusion and dobutamine-cine protocols (all p<0.001).

Clinical Implications

DHE-fSENC can triage suspected CAD patients who cannot tolerate adenosine/dobutamine, expand CMR stress testing capacity, and reduce exam time without sacrificing accuracy.

Limitations

• Reference standard of invasive angiography was available only in a subset (n=105).
• Blinding and external generalizability across centers were not detailed; clinical outcome validation was not assessed.

Future Directions

Multi-center studies with blinded reads, cost-effectiveness analyses, and outcome-based validation are needed; integration with automated strain analysis and home-based preconditioning could further scale access.