447 Left ventricular non-compaction with coronary artery anomaly: incidental diagnosis after ST-elevation myocardial infarction

Abstract

Left ventricular noncompaction (LVNC) is a rare congenital cardiomyopathy thought to be caused by arrest of normal endomyocardial morphogenesis. A 33-year-old male, smoker, dyslipidemic not on medical therapy, with family history for sudden cardiac death (SCD) presented to the ER for chest pain radiated to the left arm, unrelated to exertion. The physical examination was within normal limits. Blood tests showed increased cardiac enzymes levels (Troponin I hs 49 308.7 ng/l). The EKG showed STE in the anterior leads and diffuse ventricular repolarization anomalies, suggestive of anterior STEMI. The patient underwent coronary catheterization, with evidence of anomalous origin of the Cx from the RCA and critical stenosis on the proximal LAD, treated with PPCI and implantation of a DES with good angiographic result. The patient was transferred to the Cardiac Intensive Care Unit. TTE showed moderate LV dilatation, severe LV dysfunction (EF 30%) with apical, septal and anterior wall akinesis, and lateral wall hypertrabecularization with multiple prominent trabeculations and deep intertrabecular recesses communicating with the cavity, suggestive for LVNC. Cardiac MRI documented dilated LV with EF 34%, anterior and antero-septal wall akinesis (associated with increased T1 mapping values and areas of LGE after contrast injection, compatible with ischaemic outcomes), infero-lateral wall hypokinesia and LV free wall marked hypertrabecularization with a ratio of not compacted(T)/compacted(M) myocardium of 5 (Petersen criteria for LVNC diagnosis: T/M > 2.3 in telediastolic long-axis view). The patient was discharged in stable clinical conditions in DAPT(Cardioaspirin and Ticagrelor). At two months cardiologic follow-up the patient was asymptomatic and TTE confirmed a dilated LV with severely depressed EF (30%). In consideration of the post-ischaemic dilated cardiomyopathy with severely depressed EF and of the family history of SCD (father deceased at 54-years-old), the patient was admitted in our Cardiology Unit and he underwent subcutaneous ICD (sICD) implantation. He was discharged in stable conditions with remote home monitoring transmitter. The association between LVNC and anomalous coronary artery origin is rare. LVNC is sometimes associated with coronary artery disease, but only rare cases of acute myocardial infarction have been described in literature, with exceptionally rare cases of LVNC incidental diagnosis after STEMI. To the best of our knowledge, this is the first case of LVNC associated with anomalous coronary artery origin and STEMI reported in literature. Some authors hypothesized that a single gene responsible for both myocardial development and coronary endothelium could be involved in the pathogenesis of LVNC and at the same time predispose to coronary atherosclerosis. Further studies are necessary in order to assess the possible pathophysiological mechanisms that correlate LVNC and coronary atherosclerosis. According to European guidelines, LVNC in the absence of additional risk factors is not an indication for primary ICD implantation, and for arrhythmic risk stratification it’s recommended to follow the criteria used for non-ischaemic dilated cardiomyopathy. The anomalous origin of the Cx from the RCA has an incidence of 0.37%, and it is generally not linked to an increased risk of SCD. Involvement of RV in LVNC cannot be excluded even when RV appears normal on CMR, and if involved there is higher risk of perforation by the lead. sICD overcomes disadvantages of transvenous ICD in patients without a need for pacing therapy. In literature use of sICD is reported only in 14 patients with LVNC, mainly children and young adults.