Subtle-but-smouldering myocardial injury after immune checkpoint inhibitor treatment accompanied by amyloid deposits.

Although cardiac troponin is a highly specific biomarker for myocardial cell injury, it is important to recognize the pitfalls of this test in the diagnosis and management of immune checkpoint inhibitor (ICI) myocarditis. We describe the challenging case of an 81-year-old woman with persistently high troponin after undergoing immunotherapy with ipilimumab and nivolumab, and histological evidence of amyloid deposition in the myocardium. The patient received immunosuppressive treatments based on the magnitude of troponin changes because myocarditis was clinically suspected. However, histological examination revealed the deposition of transthyretin amyloid fibrils with only minimal T-lymphocyte infiltration and no myocyte necrosis, suggesting transthyretin cardiac amyloidosis rather than ICI myocarditis. This case highlights the importance of assessing other causes of persistently high troponin, and the necessity of incorporating comprehensive histological and immunohistochemical examinations of the endomyocardial biopsy, especially when cardiovascular magnetic resonance imaging is inconclusive.

Effect of left ventricular ejection fraction on the prognostic impact of chronic total occlusion in a non-infarct-related artery in patients with acute myocardial infarction.

BACKGROUND: Chronic total occlusion (CTO) in a non-infarct-related artery (IRA) in patients with acute coronary syndrome (ACS) is associated with a poor prognosis. However, whether the prognostic impact of non-IRA CTO differs according to left ventricular ejection fraction (LVEF) is unclear. METHODS AND RESULTS: A total of 2060 consecutive acute myocardial infarction (AMI) patients who underwent primary percutaneous coronary intervention (PCI) were classified into 2 groups according to their LVEF (reduced EF: LVEF < 50%, preserved EF: LVEF ≥ 50%) and further subdivided according to the presence of concomitant non-IRA CTO. In the reduced EF group, patients with CTO had a higher 1-year all-cause death rate (20.3% vs. 34.3%, P = 0.001) and major adverse cardiac event rate (MACE: 19.6% vs. 39.6%, P < 0.001) compared to those without CTO, but they were similar between patients with and without CTO in the preserved EF group. Non-IRA CTO was an independent predictor of all-cause death (HR 1.58, 95% CI 1.06-2.33, P = 0.02) and MACE (HR 1.67, 95% CI 1.14-2.46, P = 0.009) only in the reduced EF group. In addition, the outcomes of successful CTO-PCI seemed to be similar to those without CTO in the reduced EF group. CONCLUSIONS: CTO in a non-IRA may contribute to a poor prognosis only in AMI patients with reduced LVEF.