This article refers to ‘Recovery of cardiac function following COVID-19 – ECHOVID-19: a prospective longitudinal cohort study’ by M.C.H. Lassen et al., published in this issue on pages 1903–1912.

There has been a large number of publications concerning cardiac complications in acute coronavirus disease 2019 (COVID-19) infection.^1-5 Myocardial injury during the acute phase of COVID-19 raises the question of potential long-term cardiac implications, however, less is known about these potential consequences. Preliminary magnetic resonance imaging (MRI) based reports described common persistence of subtle cardiac injury in recovered patients.^{6, 7} However, these studies used extremely sensitive MRI protocols and lacked baseline imaging and comparison to control healthy patients. In an early echocardiographic study on survivors of COVID-19 infection, even patients with prior detection of increased troponin did not have any evidence of persistent cardiac dysfunction.⁸ However, the study included mostly patients at low risk for persistent cardiac injury, and lacked baseline imaging obtained during hospitalization. Furthermore, speckle tracking echocardiography (STE), that would detect more subtle cardiac changes, was not performed.

The first longitudinal echocardiographic study (including both baseline and follow-up echo exams) analysing the persistence of cardiac pathology following COVID-19 infection had different results.⁹ Forty-one percent of patients had right ventricular (RV) remodelling or dysfunction during acute infection, but only ≈15% had either left ventricular (LV) alone, or biventricular involvement. At 3 months post-acute infection, there was reverse RV remodelling in the majority of patients with abnormal right ventricle at baseline, but no significant changes in LV parameters. However, the study was subjected to selection bias because baseline echo during hospitalization was performed only in patients with critical disease, or clinical deterioration.

In this issue of the Journal, Lassen et al.¹⁰ used the ECHOVID-19 cohort, which is a large multicentre prospective cohort, including unselected patients with COVID-19 that underwent an echo examination according to a pre-determined research protocol, irrespective of severity of lung disease, or clinical indication. As part of the evaluation, they used both routine and STE assessment of the left and right ventricle. Follow-up echo exams were performed 2–3 months after recovery in surviving patients. Participants were matched 1:1 on age and gender, with control patients from the Copenhagen City Heart Study. The final cohort included 91 patients with baseline and follow-up echocardiography, matched with 91 control patients. Almost half of participants suffered from subclinical myocardial injury during hospitalization for COVID-19, using a broad definition including either abnormal tricuspid annular plane systolic-excursion (TAPSE), RV longitudinal strain, LV ejection fraction (LVEF), global longitudinal strain (GLS), or combination of the above. All measures of right circulation including RV functional parameters (TAPSE and RV longitudinal strain), right atrial area, or tricuspid annular area, significantly improved following the resolution of COVID-19. In contrast, LVEF decreased between the two echocardiographic examinations, and GLS did not improve. In fact, 18 (20%) continued to display LV systolic dysfunction (either abnormal LVEF or GLS) at follow-up. N-terminal pro-B-type natriuretic peptide decreased significantly between the two visits, C-reactive protein was within normal in most patients, and none of the participants had elevated troponins at follow-up. Recovered COVID-19 patients had significantly lower GLS, TAPSE, and RV longitudinal strain (but not LVEF) compared to controls.

本文参考 MCH Lassen等人在本期第 1903-1912 页上发表的“COVID-19 后心脏功能的恢复 – ECHOVID-19：一项前瞻性纵向队列研究” 。

有大量关于 2019 年急性冠状病毒病 (COVID-19) 感染心脏并发症的出版物。^1-5 COVID-19 急性期心肌损伤引发了潜在长期心脏影响的问题，但是，对这些潜在后果知之甚少。基于初步磁共振成像 (MRI) 的报告描述了康复患者中常见的轻微心脏损伤。^{6, 7}然而，这些研究使用了极其敏感的 MRI 协议，并且缺乏基线成像和对照健康患者的比较。在一项针对 COVID-19 感染幸存者的早期超声心动图研究中，即使先前检测到肌钙蛋白升高的患者也没有任何持续性心脏功能障碍的证据。⁸然而，该研究主要包括持续性心脏损伤风险低的患者，并且缺乏住院期间获得的基线影像。此外，未进行可检测更细微心脏变化的斑点跟踪超声心动图 (STE)。

第一项纵向超声心动图研究（包括基线和后续超声检查）分析了 COVID-19 感染后心脏病理的持续性，结果不同。⁹ 41% 的患者在急性感染期间有右心室 (RV) 重构或功能障碍，但只有约 15% 的患者有单独的左心室 (LV) 或双心室受累。在急性感染后 3 个月时，大多数基线时右心室异常的患者出现反向 RV 重构，但 LV 参数没有显着变化。然而，该研究存在选择偏倚，因为住院期间的基线回波仅在病情危重或临床恶化的患者中进行。

在本期杂志中，Lassen等人。¹⁰使用了 ECHOVID-19 队列，这是一个大型多中心前瞻性队列，包括未选择的 COVID-19 患者，这些患者根据预先确定的研究方案接受了回声检查，无论肺部疾病的严重程度或临床适应症如何。作为评估的一部分，他们使用了左右心室的常规和 STE 评估。在幸存患者康复后 2-3 个月进行随访超声检查。参与者在年龄和性别上与来自哥本哈根城市心脏研究的对照患者按 1:1 匹配。最后的队列包括 91 名接受基线和随访超声心动图检查的患者，与 91 名对照患者相匹配。近一半的参与者在 COVID-19 住院期间遭受亚临床心肌损伤，使用广泛的定义，包括异常三尖瓣环平面收缩偏移 (TAPSE)、RV 纵向应变、LV 射血分数 (LVEF)、整体纵向应变 (GLS) 或上述的组合。随着 COVID-19 的解决，包括 RV 功能参数（TAPSE 和 RV 纵向应变）、右心房面积或三尖瓣环面积在内的所有右循环指标均显着改善。相比之下，两次超声心动图检查之间 LVEF 下降，GLS 没有改善。事实上，18 (20%) 名患者在随访时继续表现出 LV 收缩功能障碍（LVEF 或 GLS 异常）。在两次就诊之间，N 端前 B 型利钠肽显着下降，大多数患者的 C 反应蛋白在正常范围内，并且在随访中没有参与者出现肌钙蛋白升高。