Ischaemic cardiomyopathy with a significant improvement in left ventricular wall motion following revascularization for a honeycomb-like structure of the left anterior descending artery: a case report

The honeycomb-like structure is an uncommon cause of myocardial ischaemia, detectable through high-resolution intracoronary imaging. Although percutaneous coronary intervention (PCI) for honeycomb-like structure has shown favourable outcomes, the relationship between PCI for honeycomb-like structure and subsequent improvement in cardiac function remains poorly understood.

A 58-year-old male was referred to our hospital for exertional dyspnoea. He was diagnosed with heart failure, and echocardiography revealed a reduced left ventricular ejection fraction (LVEF) of 24%, with particularly severe hypokinesis observed in the left anterior descending artery (LAD) territory. Cardiac magnetic resonance imaging showed non-transmural late gadolinium enhancement predominantly in the endocardial layer of the anterior LV wall. Coronary angiography demonstrated diffuse moderate stenosis in the LAD, with fractional flow reserve (FFR) of 0.29, and optical coherence tomography revealed a honeycomb-like structure. Two everolimus-eluting stents were implanted in the LAD. Following the PCI, significant recovery of LV wall motion including the anterior and apical segments was observed, with LVEF increasing from 24% to 46%. The 1-year follow-up showed no worsening of heart failure.

This is the first documentation of an ischaemic cardiomyopathy showing significant recovery of cardiac function after PCI targeting honeycomb-like structure. As reported in previous studies focusing on honeycomb-like structure, this case also exhibited angiographic underestimation of stenosis and low FFR value reflecting the true haemodynamic severity. The pathogenesis of honeycomb-like structure—thrombus formation and spontaneous recanalization—may have triggered ischaemic preconditioning, resulting in the development of hibernating myocardium, which could explain the viable myocardium in this case.