Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
Aix-Marseille Univ, CNRS, CRMBM, Marseille, France.
Front Endocrinol (Lausanne). 2023 Jan 25;14:1092777. doi: 10.3389/fendo.2023.1092777. eCollection 2023.
Obesity affects cardiac geometry, causing both eccentric (due to increased cardiac output) and concentric (due to insulin resistance) remodelling. Following bariatric surgery, reversal of both processes should occur. Furthermore, epicardial adipose tissue loss following bariatric surgery may reduce pericardial restraint, allowing further chamber expansion. We investigated these changes in a serial imaging study of adipose depots and cardiac geometry following bariatric surgery.
62 patients underwent cardiac magnetic resonance (CMR) before and after bariatric surgery, including 36 with short-term (median 212 days), 37 medium-term (median 428 days) and 32 long-term (median 1030 days) follow-up. CMR was used to assess cardiac geometry (left atrial volume (LAV) and left ventricular end-diastolic volume (LVEDV)), LV mass (LVM) and LV eccentricity index (LVei - a marker of pericardial restraint). Abdominal visceral (VAT) and epicardial (EAT) adipose tissue were also measured.
Patients on average had lost 21kg (38.9% excess weight loss, EWL) at 212 days and 36kg (64.7% EWL) at 1030 days following bariatric surgery. Most VAT and EAT loss (43% and 14%, p<0.0001) occurred within the first 212 days, with non-significant reductions thereafter. In the short-term LVM (7.4%), LVEDV (8.6%) and LAV (13%) all decreased (all p<0.0001), with change in cardiac output correlated with LVEDV (r=0.35,p=0.03) and LAV change (r=0.37,p=0.03). Whereas LVM continued to decrease with time (12% decrease relative to baseline at 1030 days, p<0.0001), both LAV and LVEDV had returned to baseline by 1030 days. LV mass:volume ratio (a marker of concentric hypertrophy) reached its nadir at the longest timepoint (p<0.001). At baseline, LVei correlated with baseline EAT (r=0.37,p=0.0040), and decreased significantly from 1.09 at baseline to a low of 1.04 at 428 days (p<0.0001). Furthermore, change in EAT following bariatric surgery correlated with change in LVei (r=0.43,p=0.0007).
Cardiac volumes show a biphasic response to weight loss, initially becoming smaller and then returning to pre-operative sizes by 1030 days. We propose this is due to an initial reversal of eccentric remodelling followed by reversal of concentric remodelling. Furthermore, we provide evidence for a role of EAT contributing to pericardial restraint, with EAT loss improving markers of pericardial restraint.
肥胖会影响心脏的几何形状，导致心脏发生离心（由于心输出量增加）和向心（由于胰岛素抵抗）重构。在接受减肥手术后，这两种过程都应该得到逆转。此外，减肥手术后心外膜脂肪组织的丢失可能会减少心包约束，从而进一步扩大心室。我们通过对减肥手术后脂肪组织和心脏几何形状的一系列影像学研究来研究这些变化。
62 名患者在减肥手术前后接受了心脏磁共振（CMR）检查，其中 36 名患者接受了短期（中位数 212 天）、37 名患者接受了中期（中位数 428 天）和 32 名患者接受了长期（中位数 1030 天）随访。CMR 用于评估心脏几何形状（左心房容积（LAV）和左心室舒张末期容积（LVEDV））、左心室质量（LVM）和左心室射血指数（LVei - 心包约束的标志物）。还测量了腹部内脏（VAT）和心外膜（EAT）脂肪组织。
患者平均在减肥手术后 212 天和 1030 天分别减轻了 21 公斤（38.9%的超重减轻率（EWL））和 36 公斤（64.7%的 EWL）。大多数 VAT 和 EAT 丢失（43%和 14%，p<0.0001）发生在最初的 212 天内，此后则没有明显减少。在短期中，LVM（7.4%）、LVEDV（8.6%）和 LAV（13%）均减少（均 p<0.0001），心输出量的变化与 LVEDV（r=0.35，p=0.03）和 LAV 变化（r=0.37，p=0.03）相关。尽管 LVM 随着时间的推移继续减少（与基线相比，1030 天减少 12%，p<0.0001），但到 1030 天时，LAV 和 LVEDV 均已恢复到基线水平。左心室质量/体积比值（向心性肥厚的标志物）在最长时间点达到最低点（p<0.001）。在基线时，LVei 与基线 EAT 相关（r=0.37，p=0.0040），并在 428 天时显著从基线的 1.09 下降到 1.04（p<0.0001）。此外，减肥手术后 EAT 的变化与 LVei 的变化相关（r=0.43，p=0.0007）。
心脏容积对体重减轻呈双相反应，最初会变小，然后在 1030 天内恢复到术前大小。我们认为这是由于最初的离心重构逆转，然后是向心重构逆转。此外，我们提供了证据表明 EAT 在心包约束中起作用，EAT 丢失改善了心包约束的标志物。
