背景

原发性甲状旁腺功能亢进症（primary hyperparathyroidism，PHPT）是常见的内分泌疾病，与心血管疾病风险增加相关，但其发病机制不明确，且手术对降低患者心血管疾病风险是否获益结果不一致，因此，最新的PHPT国际指南并未将心血管受累纳入手术指征。心脏收缩及舒张功能可以反映心血管疾病病情及预后。二维斑点追踪超声心动图（Two-dimensional speckle tracking echocardiography，2D-STE）较二维超声心动图（Two-dimensional echocardiography，2DE）能够更敏感、准确地评估心脏功能。然而，目前应用2D-STE评估PHPT患者心脏功能及心肌做功方面的研究非常有限。血清心脏生物标志物可作为预测心血管事件风险标志以及机制探索的基础，PHPT人群尚缺乏相关研究。免疫因素在多种心血管疾病中的作用被逐渐认识，其是否参与PHPT心血管疾病发病机制需进一步探索。

目的

（1）通过回顾性较大样本量的研究，采用2DE评估PHPT患者心脏结构与功能，分析其影响因素，并初步评估甲状旁腺手术（parathyroidectomy，PTX）是否可以改善PHPT患者心脏结构与功能。

（2）通过前瞻性研究，将2DE联合2D-STE评估PHPT患者心脏功能及心肌做功的变化，筛查与心肌损伤、炎症、纤维化相关的血清生物标志物，探索PHPT心脏受累的可能机制；进一步通过分析PHPT患者抗心肌抗体（anti-heart autoantibody，AHA），探索免疫机制在其中的作用；并通过比较PTX前后上述指标的变化评估手术对心脏受累的影响。

对象和方法

一、2DE评估PHPT心脏结构与功能的回顾性研究

纳入2015年01月至2023年12月在北京协和医院首次诊断的成人散发性PHPT患者，与PHPT组匹配年龄、性别的健康对照。收集PHPT组临床资料，采用2DE评估两组心脏结构及功能。比较两组心脏结构、功能指标差异，并应用多元逐步回归方法分析PHPT组上述指标影响因素。比较PHPT组PTX前后心脏结构、功能指标变化。

二、2DE联合2D-STE评估PHPT患者心脏功能、心肌做功，及其影响因素、可能机制的前瞻性研究

前瞻性纳入2023年03月至2024年01月在北京协和医院内分泌科就诊的成人散发性PHPT患者，其中部分患者留取血清标本。与超声心动图组按年龄、性别匹配健康对照组1，与血清生物标志物组按年龄、性别匹配对照组2。收集PHPT组临床资料，采用2DE及2D-STE评估心脏功能及心肌做功，采用流式荧光发光法测定PHPT组及对照组2受试者的血清心肌损伤、炎症、纤维化标志物，采用间接酶联免疫吸附法测定两组的AHA水平。比较PHPT患者与对照组1心脏功能、心肌做功指标的差异，比较PHPT患者与对照组2血清心脏生物标志物、AHA的差异。应用多元线性回归方法分析PHPT患者心脏功能及心肌做功指标影响因素。比较PHPT组中PTX亚组手术前后心脏功能及心肌做功指标、血清心脏生物标记物、AHA的变化。

结果

一、采用2DE回顾性评估PHPT患者心脏结构与功能

1． 纳入155例PHPT患者，平均年龄52.2±9.5岁，血总钙中位数2.79 (2.65, 2.94) mmol/L，血iPTH中位数200.5 (116.0, 455.1) pg/mL。纳入126名健康对照，平均年龄49.4±13.7岁。PHPT组LVEF、E/A显著低于对照组[LVEF: 68.1±5.9 % vs 70.9±6.4 %，P<0.001；E/A: 1.0 (0.7, 1.2) vs 1.4 (1.1, 1.6)，P<0.001]。LVMI及RWT在两组之间无显著差异。PHPT组中9%的女性患者和7.8%的男性患者存在LVMI正常、RWT>0.42。

2．在PHPT组中，分别以LVEF、E/A、LVMI、RWT为因变量，年龄、性别、病程、体质量指数、心率、高血压、糖尿病、血总钙、血磷、Ln (iPTH) 为自变量，进行多元逐步回归分析。结果显示，Ln (iPTH)是E/A（β=-0.210，P=0.003）、LVMI（β=0.287，P<0.001）的独立影响因素；血磷是RWT的独立影响因素（β=-0.246，P=0.002）。

3．44例患者PTX后复查2DE，平均年龄54.1±11.1岁，术后复查2DE时间中位数0.9 (0.4, 2.1) 年，LVEF、E/A、LVMI、RWT在手术前后无显著差异（P>0.05）。

二、2DE联合2D-STE前瞻性评估PHPT患者心脏功能、心肌做功，分析其影响因素及可能机制的研究

 1．PHPT患者术前心脏功能及心肌做功

纳入39例PHPT患者，平均年龄51.5±12.0岁，血总钙中位数2.78 (2.66, 2.91) mmol/L，血iPTH 中位数164.0 (93.1, 297.0) pg/mL。纳入34名健康对照（对照组1）。与对照组1相比，PHPT组GWE更低（93.6±3.8 % vs 95.7±1.9 %，P=0.003），平均E/e’、GWW更高（平均E/e’: 8.5±2.6 vs 7.0±2.2，P=0.011；GWW: 127.3±92.0 mmHg% vs 79.8±51.8 mmHg%，P=0.010）。其他心脏功能及心肌做功指标在两组之间无显著差异。

2．PHPT患者术前血清心脏生物标志物、AHA

（1）39例患者中有33例患者留取血清标本，并行心脏生物标志物、AHA测定。33例PHPT患者平均年龄52.0±11.6岁，平均血总钙2.86±0.33mmol/L，血iPTH 中位数179.0 (105.5, 338.8) pg/mL。纳入60名对照（对照组2），平均年龄54.5±11.9岁。PHPT组血清hs-cTnI、H-FABP、GAL-3、TG2显著高于对照组2[hs-cTnI: 44.1 (38.2, 50.6) pg/mL vs 28.1 (22.8, 35.4) pg/mL，P<0.001；H-FABP: 1.58 (1.50, 1.67) ng/mL vs 1.00 (0.77, 1.19) ng/mL，P<0.001；GAL-3: 0.15 (0.14, 0.17) ng/mL vs 0.10 (0.07, 0.17) ng/mL，P=0.001；TG2: 0.47 (0.43, 0.48) ng/mL vs 0.23 (0.19, 0.30) ng/mL，P<0.001]。AHA指标在两组间无显著差异。

（2）将PHPT患者术前血清hs-cTnI、H-FABP与人口学数据、合并疾病、PHPT相关生化指标、AHA进行单因素相关性分析，没有发现hs-cTnI、H-FABP与上述变量具有相关性。

3．PHPT患者术前心脏功能及心肌做功影响因素

对33例进行了术前血清心脏生物标志物、AHA检测的PHPT患者，进一步分析其心脏功能、心肌做功指标与PHPT临床指标、血清心脏生物标志物、AHA的相关性。多元线性回归分析结果显示：平均E/e’与GWW呈独立正相关（β=0.357，P=0.038）；GWW与Log(GDF15)具有独立负相关趋势（β=-0.316，P=0.052）。

4．PTX对PHPT患者心脏功能、心肌做功指标、血清心脏生物标志物、AHA的影响

（1）28例患者行PTX，其中11例患者术后复查2DE、2D-STE，平均年龄50.8±12.9岁，术后复查2DE、2D-STE平均时间3.9±1.8月。与术前相比，术后GWE有增加趋势（95.3±2.6 % vs 93.8±3.9 %，P=0.062）。心脏功能、心肌做功其他指标在手术前后无显著变化。

（2）11例患者中有7例患者复查血清心脏生物标志物及AHA。7例患者平均年龄48.9±16.0岁，术后复查时间4.7±1.6月。相较于术前，术后血清hs-cTnI、H-FABP、GDF15、GAL-3、IL1RL1、TG2、iFGF23均显著降低（P<0.05），L-Cac-Ab升高（59.9±12.1 ng/mL vs 41.3±15.8 ng/mL，P<0.05）。

（3）将7例PHPT患者血总钙、血磷、血iPTH手术前后变化值与血清心脏生物标志物、L-Cac-Ab手术前后变化值进行相关性分析显示：Δ血钙与ΔH-FABP（r=0.785, P=0.036）、ΔTG2呈正相关（r=0.969，P<0.001），Δ血磷与ΔiFGF23呈负相关（r=-0.762，P=0.047）。将7例PHPT患者术前血总钙、血磷、血iPTH与血清心脏生物标志物、L-Cac-Ab手术前后变化值进行相关性分析显示：术前血钙水平与ΔTG2呈正相关（r=0.906，P=0.005），术前血磷水平与ΔiFGF23呈负相关（r=-0.870，P=0.011），术前iPTH水平与ΔiFGF23呈正相关（r=0.786，P=0.036）。

结论

一、通过较大样本量的回顾性研究显示，基于常规二维超声心动图，本组PHPT患者LVEF和E/A显著降低，提示存在心脏收缩及舒张功能下降；可能存在以向心性重构为特征的心脏几何形状异常。高水平PTH与E/A降低、LVMI增加相关，低血磷与RWT增加相关。在相对小样本量的亚组中没有观察到PTX可以改善PHPT患者心脏结构及功能。

二、通过前瞻性研究显示：

1. 本队列PHPT患者平均E/e’、整体无效功增加，整体做功效率降低。

2. PHPT患者血清心肌损伤、炎症及纤维化标志物升高。

3. 本研究没有发现PHPT患者常见血清AHA指标的变化，以及AHA与PHPT临床指标的相关性。

4. 心脏舒张功能指标平均E/e’与GWW呈独立正相关，GWW与GDF15呈独立负相关趋势。

5. 在小样本量的亚组中观察到PTX术后短期（3-6个月）PHPT患者血清心肌损伤、炎症及纤维化标志物水平的显著降低，整体做功效率有改善趋势。手术前后血钙、血磷的变化幅度以及术前血钙、血磷及PTH水平与术后血清心肌损伤、心肌纤维化标志物下降幅度有关。

Background

Primary hyperparathyroidism (PHPT) is a common endocrinopathy and associated with an increased risk of cardiovascular disease. However, the pathogenesis of cardiovascular disease in PHPT remains unclear. And there are contradictory research results about the benefits of surgery in reducing the risk of cardiovascular disease. Therefore, the latest PHPT international guidelines do not include cardiovascular involvement as a surgical indication. The cardiac systolic and diastolic functions can reflect the severity and prognosis of cardiovascular disease. Compared to two-dimensional echocardiography (2DE), two-dimensional speckle tracking echocardiography (2D-STE) can assess cardiac function more sensitively and accurately. However, research on the application of 2D-STE to evaluate cardiac function and myocardial work in PHPT patients is still limited. Serum cardiac biomarkers can serve as predictors of cardiovascular event risk and as bases of exploring potential mechanisms, but relevant studies are lacking in PHPT patients. The role of autoimmunity in cardiovascular diseases is gradually being recognized, and further exploration is needed to determine whether it is involved in the pathogenesis of cardiovascular disease in PHPT.

Objective

(1) A retrospective study with a large sample size was conducted to evaluate the cardiac structure and function of PHPT patients using 2DE and investigate their influencing factors, as well as assess whether parathyroidectomy (PTX) can improve the cardiac structure and function of PHPT patients.

(2) A prospective study was performed to evaluate the cardiac function and myocardial work of PHPT patients utilizing both 2DE and 2D-STE, screen for serum biomarkers related to myocardial injury, inflammation, and fibrosis, explore possible mechanisms of cardiac disease; further explore the role of immune mechanisms by detecting anti-heart autoantibody (AHA) in PHPT patients; and assess the impact of PTX on cardiac function, myocardial work and serum parameters mentioned above.

Subjects and Methods

A retrospective study using 2DE to evaluate cardiac structure and function of PHPT patients.

Adult patients diagnosed with sporadic PHPT for the first time at Peking Union Medical College Hospital (PUMCH) from January 2015 to December 2023 were included. They were matched with healthy controls for age and sex. The clinical data of PHPT patients were collected. Cardiac structure and function were assessed by 2DE both groups. Differences in cardiac structure and function indices between the two groups were compared, and factors affecting these indices were analyzed by multiple stepwise regression analysis in the PHPT group. Changes in cardiac structure and function indicators before and after PTX of the PHPT group were also compared.

(2) A prospective study on evaluation of cardiac function and myocardial work using 2DE and 2D-STE and on exploration of potential mechanisms of cardiac function and myocardial work in PHPT patients.

Adult sporadic PHPT patients who visited PUMCH from March 2023 to January 2024 were prospectively enrolled (defined as PHPT group). The clinical data were collected in PHPT group. The cardiac function and myocardial work of the PHPT group, assessed by 2DE and 2D-STE, were compared with those of an age- and sex-matched healthy control group (control group 1). Part of PHPT patients were matched with healthy controls by sex and age (control group 2), and both of them had testing of serum markers of myocardial injury, inflammation, and fibrosis using the flowcytometry fluorescence luminance method, the AHA level using indirect enzyme linked immunosorbent assay and were compared with each other. Multiple linear regression analysis was conducted for investigating the influential factors of cardiac function and myocardial work in the PHPT group. Changes in cardiac function and myocardial work indicators, serum cardiac biomarkers and AHA before and after PTX were analyzed in PHPT subgroup.

Results

(1) The characteristics of cardiac structure and function using 2DE in PHPT patients in a retrospective study.

1. A total of 155 PHPT patients and 126 matched healthy controls were enrolled, with mean ages of 52.2±9.5 years and 49.4±13.7 years, respectively. The PHPT patients had a median serum calcium of 2.79 (2.65, 2.94) mmol/L and a median serum intact parathyroid hormone (iPTH) of 200.5 (116.0, 455.1) pg/mL. Compared with the control group, the PHPT group exhibited significantly lower left ventricular ejection fraction (LVEF: 68.1±5.9 % vs 70.9±6.4 %, P<0.001) and E/A ratio [E/A: 1.0 (0.7, 1.2) vs 1.4 (1.1, 1.6), P<0.001], while there was no difference in left ventricular mass index (LVMI) and relative wall thickness (RWT) between the two groups. 9.0% of female and 7.8% of male PHPT patients had normal LVMI with RWT>0.42.

2. In the PHPT group, multiple stepwise regression analyses were conducted with LVEF, E/A, LVMI and RWT as dependent variables, and age, sex, disease duration, body mass index, heart rate, hypertension, diabetes mellitus, serum calcium, serum phosphate, and Ln(iPTH) as independent variables. The results suggested that Ln(iPTH) was an independent influencing factor for E/A (β=-0.210, P=0.003) and LVMI (β=0.287, P<0.001), and serum phosphate was an independent influencing factor for RWT (β=-0.246, P=0.002).

3. Forty-four PHPT patients underwent 2DE again after PTX, with a mean age of 54.1±11.1 years and a median time to postoperative 2DE of 0.9 (0.4, 2.1) years. There were no significant differences in LVEF, E/A, LVMI and RWT before and after PTX (P>0.05).

(2) The characteristics and potential mechanisms of cardiac function and myocardial work using 2DE and 2D-STE in PHPT patients in a prospective study.

1. Preoperative cardiac function and myocardial work in PHPT patients

A total of 39 PHPT patients and 34 matched healthy controls (control group 1) were enrolled. These PHPT patients had a mean age of 51.5±12.0 years, median serum calcium of 2.78 (2.66, 2.91) mmol/L, and median serum iPTH of 164.0 (93.1, 297.0) pg/mL. Compared with control group 1, PHPT patients had lower global work efficiency (GWE: 93.6±3.8 % vs 95.7±1.9 %, P=0.003), and higher average E/e' (8.5±2.6 vs 7.0±2.2, P=0.011) and global wasted work (GWW: 127.3±92.0 mmHg% vs 79.8±51.8 mmHg%, P=0.010).

2. Preoperative serum cardiac biomarkers and AHA in PHPT patients

2.1. Blood sample was collected from 33 out of 39 PHPT patients and 60 matched healthy controls (control group 2). The PHPT patients had a mean age of 52.0±11.6 years, mean serum calcium of 2.86±0.33 mmol/L and median serum iPTH of 179.0 (105.5, 338.8) pg/mL. The serum hs-cTnI, H-FABP, GAL-3, and TG2 in the PHPT group were significantly higher than those in the control group 2 [hs-cTnI: 44.1 (38.2, 50.6) pg/mL vs 28.1 (22.8, 35.4) pg/mL, P<0.001; H-FABP: 1.58 (1.50, 1.67) ng/mL vs 1.00 (0.77, 1.19) ng/mL, P<0.001; GAL-3: 0.15 (0.14, 0.17) ng/mL vs 0.10 (0.07, 0.17) ng/mL, P=0.001; TG2: 0.47 (0.43, 0.48) ng/mL vs 0.23 (0.19, 0.30) ng/mL, P<0.001]. AHA did not differ significantly between the two groups.

2.2. A univariate correlation analysis was conducted between the preoperative serum hs-cTnI, H-FABP and demographic data, comorbidities, PHPT related biochemical indicators, AHA. No correlation was found between hs-cTnI, H-FABP and the above variables.

3. Factors influencing preoperative cardiac function and myocardial work in PHPT Patients

Multiple linear regression analysis was applied in the 33 PHPT patients, to analyze the correlation between the indicators of cardiac function and myocardial work and the clinical parameters, serum cardiac biomarkers and AHA. The results showed that average E/e’ was independently positively correlated with GWW (β=0.357, P=0.038). GWW was independently negatively correlated with Log(GDF15) (β=-0.316, P=0.052).

4. The effects of PTX on cardiac function, myocardial work, serum cardiac biomarkers, and AHA in PHPT patients

4.1. Among 28 PHPT patients who underwent PTX, 11 cases re-examined 2DE and 2D-STE after surgery, with a mean age of 50.8±12.9 years, and the mean time to postoperative 2DE and 2D-STE was 3.9±1.8 months. Compared to preoperative, postoperative GWE shows an increasing trend (95.3±2.6 % vs 93.8±3.9%, P=0.062). There was no change in cardiac function, and other myocardial work indicators before and after PTX.

4.2. Among the 11 PHPT patients, 7 patients re-examined the serum cardiac biomarkers and AHA after PTX, with a mean age of 48.9±16.0 years, and the mean time to re-examination was 4.7±1.6 months. Several serum biomarkers, including hs-cTnI, H-FABP, GDF15, GAL-3, IL1RL1, TG2, iFGF23, showed significant postoperative reductions compared to their preoperative levels (all P<0.05), while L-Cac-Ab increased after PTX (59.9±12.1 ng/mL vs 41.3±15.8 ng/mL, P<0.05).

4.3. The correlation analysis was performed between change in serum calcium, serum phosphorus, serum iPTH, and the change in serum cardiac biomarkers and L-Cac-Ab level in 7 PHPT patients. The results revealed that Δcalcium was positively correlated with ΔH-FABP (r=0.785, P=0.036) and ΔTG2 (r=0.969, P<0.001), Δphosphorus was negatively correlated with Δ iFGF23 (r=-0.762 P=0.047). The correlation analysis was performed between pre-PTX serum calcium, serum phosphorus, serum iPTH, and the change in serum cardiac biomarkers and L-Cac-Ab in 7 PHPT patients. The results revealed that pre-PTX serum calcium level was positively correlated with ΔTG2 (r=0.906, P=0.005), serum phosphorus level was negatively correlated with ΔiFGF23 (r=-0.870, P=0.011), serum iPTH level was positively correlated with Δ iFGF23 (r=0.786, P=0.036).

Conclusions

(1) The retrospective study with a large sample size show that patients with PHPT exhibit significantly decreased LVEF and E/A using two-dimensional echocardiography, suggesting impaired cardiac systolic and diastolic function, possibly indicating cardiac geometric abnormalities characterized by concentric remodeling. Elevated PTH level is associated with decreased E/A and increased LVMI, while low serum phosphorus is associated with increased RWT. In a relatively small subgroup, no improvement in cardiac structural and functional parameters of PHPT patients is observed after PTX.

(2) Findings from the prospective study:

1. PHPT patients have higher average E/e’ and GWW, and lower GWE than healthy controls.

2. Serum markers of myocardial injury, inflammation, and fibrosis are increased in PHPT patients.

3. There is no evidence that the changes in serum AHA indicators as well as the correlation between AHA and clinical indicators of PHPT patients.

4. Elevated GWW result in impaired cardiac diastolic function. GWW is independently negatively correlated with serum GDF15 level.

5. In a small subgroup, it is observed that serum markers of myocardial injury, inflammation, fibrosis decrease, and GWE increase after PTX in PHPT patients. The change of serum calcium and phosphorus before and after PTX, as well as preoperative serum calcium, phosphorus, and PTH levels are related to the extent of decrease in serum markers of myocardial fibrosis after surgery.