Hypothyroidism is a Risk Factor for Atrial Fibrillation after Coronary Artery Bypass Graft

Effects of Preoperative Nutritional Status and Lymphocyte Count on the Development of Early-term Atrial Fibrillation After Coronary Artery Bypass Grafting: A Retrospective Study

INTRODUCTION

Although there are publications in the literature stating that parameters related to the nutritional status of patients are associated with the clinical outcomes of those with coronary artery disease, it is also stated that there is insufficient data on the relationship between nutritional indices and long-term outcomes and major adverse cardiovascular events in patients undergoing isolated coronary artery bypass grafting.

METHODS

This retrospective study was conducted with patients who underwent isolated elective on-pump coronary artery bypass grafting in our hospital. Patients who underwent emergency coronary artery bypass grafting or those with known atrial fibrillation in the preoperative period were excluded. Patients were analyzed and compared in two groups according to the development of postoperative atrial fibrillation.

RESULTS

The data of 93 coronary artery bypass grafting patients (71 [76%] males) with a mean age of 62.86 ± 9.53 years included in the study were evaluated. Both groups had similar preoperative ejection fraction value, hemoglobin level, age, number of distal bypasses, and postoperative mortality rates. Although the mean cardiopulmonary bypass and aortic cross-clamping times were higher in Group 1, they were not statistically significant. In our study, the mean prognostic nutrition index value was 51.76 ± 3002.

CONCLUSION

According to our study results, there was no statistically significant difference between prognostic nutrition index values and the development of atrial fibrillation after coronary artery bypass grafting, which is similar to some publications in the literature. We think that it would be beneficial to conduct randomized studies involving more patients on this subject.

Effect of hypothyroidism on short-term outcomes after autologous and implant-based breast reconstruction

Hypothyroidism has high prevalence in elderly women, which overlaps with the patient population who opt for post-mastectomy breast reconstruction. While hypothyroidism was shown to impact outcomes in other surgeries, its effect on breast reconstruction has not been established. This study aimed to compare the short-term outcomes of patients with and without hypothyroidism who underwent autologous (ABR) and implant-based breast reconstruction (IBR), respectively. Patients having ABR or IBR were identified in the National Inpatient Sample from Q4 2015-2020. Multivariable logistic regressions were used to compare in-hospital outcomes between patients with and without hypothyroidism, adjusted for demographics, socioeconomic status, comorbidities, and hospital characteristics. There were 12,765 patients underwent ABR, where 1591 (12.46%) of them had hypothyroidism, while 17,670 patients had IBR with 1,984 (11.23%) having hypothyroidism. Hypothyroid patients had a higher risk of hemorrhage/hematoma (aOR = 1.254, 95 CI 1.079-1.457, p < 0.01) after ABR. However, there were no differences in terms of mortality and organ system complications, nor wound dehiscence, superficial/deep wound complications, seroma, flap revision, excessive scarring, venous thromboembolism, pulmonary embolism, vascular complications, infection, sepsis, transfer out, length of stay (LOS), nor hospital charge between patients with and without hypothyroidism after ABR. All postoperative outcomes were comparable between hypothyroid patients and controls after IBR. While breast reconstruction is generally safe for hypothyroid patients, preoperative screening for hypothyroidism may be beneficial for those undergoing ABR. In ABR, hypothyroidism correction and blood management may help prevent bleeding complications in hypothyroid patients. Future studies should explore the long-term prognosis of hypothyroid patients after breast reconstruction.

Clinical factors associated with arrhythmia and short-term prognosis following mitral valve repair: a retrospective cohort study

BACKGROUND

Postoperative arrhythmia (POA) is one of the common and serious postoperative complications. This retrospective study was conducted to investigate the clinical factors associated with POA and its short-term prognosis following mitral valve repair.

METHODS

A total of 618 patients receiving mitral valve repair between January 2015 and November 2020 in our hospital were included in this retrospective study, including 318 males and 300 females and aged 53.9±9.3 years. The patients were grouped into arrhythmia and non-arrhythmia groups and investigated for risk factors associated with the prognosis of POA using multivariate logistic regression based on their clinical data.

RESULTS

POA was observed in 314 (50.8%) patients and atrial fibrillation (AF) was the most frequent (43.3%) type of POA. Compared with non-arrhythmia patients, arrhythmia patients had significantly longer time to use vasoactive drug use, longer intensive care unit (ICU) stay and longer hospital stay. In addition, the incidence of postoperative heart failure was significantly higher (P<0.05). Logistic regression analysis showed that preoperative arrhythmia [odds ratio (OR) =9.17; 95% confident interval (CI): 4.49-18.10], postoperative pain (OR =4.70; 95% CI: 1.55-6.12) and postoperative hypoxemia (OR =3.25; 95% CI: 1.04-6.28) were independently associated with POA.

CONCLUSIONS

This study demonstrates that the incidence of arrhythmia is relatively high after mitral valve repair and is associated with preoperative arrhythmia, postoperative pain and postoperative hypoxemia.

New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation

Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.

Impact of Hypothyroidism on Echocardiographic Characteristics of Patients With Heart Valve Disease: A Single-Center Propensity Score-Based Study

Background: Hypothyroidism is known to be correlated with multiple heart diseases. However, the influence of hypothyroidism on the patients with heart valve disease (HVD) is still unclear. The purpose of our study was to investigate the impact of hypothyroidism on echocardiographic characteristics of patients with heart valve disease. Methods: We conducted a retrospective cohort study which included 2,128 patients with HVD, and they were divided into euthyroid, subclinical hypothyroidism (SCHypoT), and overt hypothyroidism (OHypoT) group. Echocardiographic characteristics before and after valve surgery between groups were compared by using propensity score (PS) analysis. Kaplan-Meier analysis was used to compare the percent of recovery of left atrial (LA) enlargement between groups. Results: Overall, 463 patients had hypothyroidism (404 SCHypoT patients and 59 OHypoT patients), and 1,665 patients were euthyroid. At baseline, hypothyroidism was associated with significantly higher left atrial diameter (LAD), interventricular septum thickness, left ventricular posterior wall thickness, pulmonary artery systolic pressure, and lower left ventricular ejection fraction. After valve surgery, only LAD remained significantly higher in the patients with hypothyroidism. Additionally, patients with hypothyroidism had a significantly lower recovery rate of LA enlargement after valve surgery compared with euthyroid patients. Conclusion: Hypothyroidism was associated with a larger LAD in patients with HVD before and after surgery, which may suggest that hypothyroidism is a risk factor of LA enlargement of HVD. Besides, hypothyroidism was associated with a significantly lower recovery rate of LA enlargement after valve surgery.

Hypothyroidism as a Predictor of Surgical Outcomes in the Elderly

There is a high prevalence of hypothyroidism in the elderly population, mainly among women. The most important cause is autoimmune thyroiditis, but also iodine deficiency, radioiodine ablation, and surgery may be responsible for hypothyroidism in elderly hospitalized patients. Thyroid-related symptoms are sometimes comparable to physiological manifestations of the aging process, and hypothyroidism may be related with many symptoms which can be present in critical patients, such as cognitive impairment, cardiovascular, gastrointestinal, and hematological alterations, and eventually myxedema coma which is a severe and life-threatening condition in older adults. Adequate thyroid hormone levels are required to achieve optimal outcomes from any kind of surgical intervention. However, only few randomized clinical trials investigated the association between non-thyroidal illness (or low-T3 syndrome), and adverse surgical outcomes, so far. The goal of this review is to discuss the role of thyroid function as a predictor of surgical outcomes in the elderly.