Introduction: Pheochromocytoma is a catecholamine-secreting tumor with diverse cardiovascular manifestations, including myocardial infarction with non-obstructive coronary arteries (MINOCA). We report a case of biochemically confirmed pheochromocytoma initially presenting as non-ST-elevation myocardial infarction (NSTEMI), later reclassified as MINOCA. Case: A 62-year-old female with type 2 diabetes mellitus and hypertension was admitted with presumed NSTEMI and commenced on dual antiplatelet therapy. Further history revealed recurrent presyncope associated with paroxysmal headache, palpitations, and profuse diaphoresis. During admission, her blood pressure was markedly labile, ranging from 75/45 to 220/122 mmHg, raising suspicion of pheochromocytoma. Biochemical evaluation demonstrated markedly elevated 24-hour urinary normetanephrine of 36.19 µmol/day (reference 0–2.13) and methoxytyramine of 3.90 µmol/day (reference 0.10– 1.79), consistent with catecholamine excess. Dedicated adrenal computed tomography identified a 3.8-cm right adrenal lesion with high attenuation (44 Hounsfield Unit [HU]), arterial enhancement (119 HU), and low washout (absolute 40%, relative 24%), without calcification or necrosis. Electrocardiography showed sinus rhythm with T-wave inversion in leads I, aVL, and V5–V6. Transthoracic echocardiography demonstrated a preserved left ventricular ejection fraction of 67% without regional wallmotion abnormalities. Coronary angiography subsequently showed normal coronary arteries, supporting a diagnosis of MINOCA likely secondary to pheochromocytoma-related catecholamine excess and hypertensive crisis. Antiplatelets were discontinued. She was commenced on α-blockade, with additional felodipine and low-dose β-blocker for blood pressure optimization, and subsequently underwent successful open right adrenalectomy. Postoperatively, she required transient inotropic support but was weaned within 36 hours. Conclusion Pheochromocytoma-associated MINOCA is uncommon but important to recognize. Catecholamine surges may cause myocardial injury through coronary vasospasm, myocardial oxygen supply-demand mismatch, and direct catecholamine-mediated cardiotoxicity. Recognition is crucial, as management differs fundamentally from atherosclerotic acute coronary syndrome and requires α-blockade before β-blockade.
MINOCA ; Non-ST Elevated Myocardial Infarction ; Pheochromocytoma

Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.
Male ; Female ; Humans ; Aged ; Natriuretic Peptide, Brain ; Simendan/therapeutic use* ; Non-ST Elevated Myocardial Infarction ; Heart Failure/drug therapy* ; Peptide Fragments ; Arrhythmias, Cardiac ; Biomarkers ; Prognosis