Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
Department of Endocrinology, Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, United Kingdom.
J Am Coll Cardiol. 2016 May 24;67(20):2364-2374. doi: 10.1016/j.jacc.2016.03.543.
Pheochromocytoma is associated with catecholamine-induced cardiac toxicity, but the extent and nature of cardiac involvement in clinical cohorts is not well-characterized.
This study characterized the cardiac phenotype in patients with pheochromocytoma using cardiac magnetic resonance (CMR).
A total of 125 subjects were studied, including patients with newly diagnosed pheochromocytoma (n = 29), patients with previously surgically cured pheochromocytoma (n = 31), healthy control subjects (n = 51), and hypertensive control subjects (HTN) (n = 14), using CMR (1.5-T) cine, strain imaging by myocardial tagging, late gadolinium enhancement, and native T1 mapping (Shortened Modified Look-Locker Inversion recovery [ShMOLLI]).
Patients who were newly diagnosed with pheochromocytoma, compared with healthy and HTN control subjects, had impaired left ventricular (LV) ejection fraction (<56% in 38% of patients), peak systolic circumferential strain (p < 0.05), and diastolic strain rate (p < 0.05). They had higher myocardial T1 (974 ± 25 ms, as compared with 954 ± 16 ms in healthy and 958 ± 23 ms in HTN subjects; p < 0.05), areas of myocarditis (median 22% LV with T1 >990 ms, as compared with 1% in healthy and 2% in HTN subjects; p < 0.05), and focal fibrosis (59% had nonischemic late gadolinium enhancement, as compared with 14% in HTN subjects). Post-operatively, impaired LV ejection fraction typically normalized, but systolic and diastolic strain impairment persisted. Focal fibrosis (median 5% LV) and T1 abnormalities (median 12% LV) remained, the latter of which may suggest some diffuse fibrosis. Previously cured patients demonstrated abnormal diastolic strain rate (p < 0.001), myocardial T1 (median 12% LV), and small areas of focal fibrosis (median 1% LV). LV mass index was increased in HTN compared with healthy control subjects (p < 0.05), but not in the 2 pheochromocytoma groups.
This first systematic CMR study characterizing the cardiac phenotype in pheochromocytoma showed that cardiac involvement was frequent and, for some variables, persisted after curative surgery. These effects surpass those of hypertensive heart disease alone, supporting a direct role of catecholamine toxicity that may produce subtle but long-lasting myocardial alterations.
嗜铬细胞瘤与儿茶酚胺诱导的心脏毒性有关，但临床队列中心脏受累的程度和性质尚不清楚。
本研究通过心脏磁共振（CMR）对嗜铬细胞瘤患者的心脏表型进行了特征描述。
共纳入 125 名受试者，包括新诊断的嗜铬细胞瘤患者（n=29）、既往手术治愈的嗜铬细胞瘤患者（n=31）、健康对照组（n=51）和高血压对照组（HTN）（n=14），采用 CMR（1.5-T）电影、心肌标记应变成像、晚期钆增强和原生 T1 映射（缩短改良 Look-Locker 反转恢复[ShMOLLI]）。
与健康对照组和 HTN 对照组相比，新诊断的嗜铬细胞瘤患者的左心室（LV）射血分数降低（38%的患者<56%），峰值收缩环周应变降低（p<0.05），舒张应变率降低（p<0.05）。他们的心肌 T1 较高（974±25ms，而健康对照组为 954±16ms，HTN 对照组为 958±23ms；p<0.05），心肌炎面积较大（中位数 22%LV 的 T1>990ms，而健康对照组为 1%，HTN 对照组为 2%；p<0.05），局灶性纤维化（59%的患者存在非缺血性晚期钆增强，而 HTN 对照组为 14%）。术后，LV 射血分数通常恢复正常，但收缩和舒张应变受损仍持续存在。局灶性纤维化（中位数 5%LV）和 T1 异常（中位数 12%LV）仍然存在，后者可能提示存在一些弥散性纤维化。既往治愈的患者表现出舒张应变率异常（p<0.001）、心肌 T1（中位数 12%LV）和小面积局灶性纤维化（中位数 1%LV）。与健康对照组相比，HTN 组的 LV 质量指数增加（p<0.05），但在 2 个嗜铬细胞瘤组中并未增加。
本项首次采用 CMR 系统描述嗜铬细胞瘤患者心脏表型的研究表明，心脏受累很常见，并且在一些变量中，在根治性手术后仍然存在。这些影响超过了单纯高血压性心脏病的影响，支持儿茶酚胺毒性的直接作用，可能导致微妙但持久的心肌改变。
