Subclinical Hypothyroidism and Clinical Outcomes After Percutaneous Coronary Intervention: A Meta-Analysis

Impact of subclinical hypothyroidism on outcomes after coronary artery bypass grafting: a systematic review and meta-analysis

INTRODUCTION

Coronary artery bypass grafting (CABG) is a surgical procedure that restores blood flow to heart muscle by bypassing the blocked or narrowed coronary arteries. On the other hand, subclinical hypothyroidism (SCH) is characterized by an elevated serum concentration of thyroid stimulating hormone with normal levels of serum free thyroxine. With limited research into the impact of SCH on postoperative CABG outcomes, this systematic review and meta-analysis was performed.

EVIDENCE ACQUISITION

An electronic search of PubMed, Cochrane Library, and Scopus was performed from inception to April 2023. After the inclusion of five studies, a total of 2,786 patients were pooled in this quantitative synthesis.

EVIDENCE SYNTHESIS

It was observed that SCH significantly increased cardiovascular mortality (OR: 2.80; 95% CI: 1.37, 5.72; P=0.005), and all-cause mortality (OR: 2.62; 95% CI: 1.80, 3.80; P<0.00001). However, no significant differences were observed for secondary outcomes, including major adverse cardiac events, incidence of postoperative stroke, and incidence of postoperative myocardial infarction.

CONCLUSIONS

To the best of our knowledge, this is the first meta-analysis conducted that evaluates the impact of SCH on outcomes after CABG. The preoperative assessment of thyroid function may be considered prior to cardiovascular procedures, particularly within CABG. However, future comprehensive studies, with individual participant-level data, are necessary in order to arrive at a valid conclusion and recommendation.

Subclinical hypothyroidism and clinical outcomes after cardiac surgery: A systematic review and meta-analysis

Background

Subclinical hypothyroidism (SCH) is associated with major adverse cardiovascular events. Despite the recognized negative impact of SCH on cardiovascular health, research on cardiac postoperative outcomes with SCH has yielded conflicting results, and patients are not currently treated for SCH before cardiac surgery procedures.

Methods

We performed a study-level meta-analysis on the impact of SCH on patients undergoing nonurgent cardiac surgery, including coronary artery bypass grafting and valve and aortic surgery. The primary outcome was operative mortality. Secondary outcomes were hospital length of stay (LOS), intensive care unit (ICU) stay, postoperative atrial fibrillation (POAF), intra-aortic balloon pump (IABP) use, renal complications, and long-term all-cause mortality.

Results

Seven observational studies, with a total of 3445 patients, including 851 [24.7%] diagnosed with SCH and 2594 [75.3%] euthyroid patients) were identified. Compared to euthyroid patients, the patients with SCH had higher rates of operative mortality (odds ratio [OR], 2.57; 95% confidence interval [CI], 1.09-6.04; P = .03), prolonged hospital LOS (standardized mean difference, 0.32; 95% CI, 0.02-0.62; P = .04), a higher rate of renal complications (OR, 2.53; 95% CI, 1.74-3.69; P < .0001), but no significant differences in ICU stay, POAF, or IABP use. At mean follow-up of 49.3 months, the presence of SCH was associated with a higher rate of all-cause mortality (incidence rate ratio, 1.82; 95% CI, 1.18-2.83; P = .02).

Conclusions

Patients with SCH have higher operative mortality, prolonged hospital LOS, and increased renal complications after cardiac surgery. Achieving and maintaining a euthyroid state prior to and after cardiac surgery procedures might improve outcomes in these patients.

Association between calcium supplementation and gestational hypertension, and preeclampsia: A Meta-analysis of 26 randomized controlled trials

BACKGROUND

Pre-eclampsia and eclampsia are common causes of morbidity and mortality, especially in low-income countries. Reducing adverse outcomes associated with hypertensive disorders of pregnancy has been the ultimate priority in recent years. We aim to evaluate the association between calcium supplementation and preeclampsia and gestational hypertension risk among pregnant women.

METHODS

A systematic literature search was performed in electronic databases from inception to 15th July 2023, including only randomized controlled trials. Odds ratio (OR) were, and their corresponding 95% confidence interval (95% CI).

RESULTS

A total of 26 studies with 20,038 patients (10,003 patients with calcium supplements and 10,035 patients with placebo group) were included in the analysis. The Pooled analysis of primary outcome shows that calcium supplements reduce the risk of preeclampsia by 49% (OR, 0.51(95%CI: 0.40-0.66), P<0.001), and reduce the risk of gestational hypertension by 30% (OR, 0.70 (95%CI: 0.58-0.85)), P<0.001) compared to placebo. There was a trend of lower incidence of preterm delivery (OR, 0.88 (95%CI: 0.71-1.09), P=0.23), labor induction (OR, 0.90 (95%CI: 0.78-1.03), P=0.13), small for gestational age (OR, 0.70 (95% CI:0.37-1.32), P = 0.27), low birth weight (OR, 0.96 (95%CI: 0.86-1.08), P=0.53), perinatal mortality (OR, 0.88 (95%CI: 0.72-1.09), P=0.24), and maternal mortality (OR, 0.48 (95%CI: 0.12-1.84), P=0.28) among calcium supplementation group compared with the placebo group, however, statistical signifance was not achieved.

CONCLUSION

This study shows that calcium supplements are associated with a significant reduction in the risk of preeclampsia and gestational hypertension and a trend toward better maternal and fetal-related outcomes.

A review regarding the article 'systematic review and meta-analysis of levothyroxine effect on blood pressure in patients with subclinical hypothyroidism'

Subclinical hypothyroidism (SCH) is a biochemical condition defined by elevated serum thyroid stimulating hormone levels in the setting of normal levels of the peripheral thyroid hormones, thyroxine, and triiodothyronine. SCH is becoming increasingly prevalent in recent years especially among the elderly, and its prevalence ranges approximately from 5 to 20% in the general population. Clinical manifestations of SCH range from obvious symptoms to no signs or symptoms, and the most common symptoms of SCH include fatigue, mild depression, muscle weakness, cold intolerance, and weight gain. However, despite the clear biochemical pattern of mild thyroid failure, few patients with SCH have typical hypothyroid symptoms. Patients with SCH have elevated blood pressure, but the effect of levothyroxine (LT4) therapy on blood pressure among those patients is still unclear. Severe SCH or mild SCH with symptoms are generally recommended to be treated with levothyroxine (LT4), which requires monitoring of TSH level over several months and adjusting LT4 dosage accordingly. Oral LT4 administered daily is the treatment of choice for SCH, and the goal of LT4 treatment for SCH is to restore the TSH level within the reference range.

Post-diagnostic statin use and its association with cancer recurrence and mortality in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Statins are widely acknowledged for their application in patients with hypercholesterolemia to reduce cardiovascular morbidity and mortality. More recently, their potential to exert pleiotropic effects, particularly in impeding the proliferation of neoplastic cells, has attracted considerable attention. Prior studies have demonstrated that statins may mitigate cancer progression and micrometastasis. However, the benefits of statins in breast cancer have been inconclusive.

OBJECTIVE

The aim of this meta-analysis was to evaluate the impact of statin use following a breast cancer diagnosis on breast cancer recurrence and mortality.

METHODS

We performed a systematic literature search using PubMed, Embase, and Scopus for relevant articles from inception until 30th May 2023. Hazard ratios (HR) were pooled using a random-effect model. The primary outcome of interest was the risk of breast cancer recurrence. The secondary outcomes included breast cancer-specific mortality and all-cause mortality.

RESULTS

A total of 15 studies with 156 448 patients were included in the final analysis. The mean age of patients between statin users and non-users was 64.59 and 59.15 years, respectively. Statin use was associated with a reduction in the recurrence of breast cancer [HR 0.76, 95% confidence interval (CI): 0.67-0.87] compared with non-statin users. This trend was similar among lipophilic statin users (HR 0.73, 95% CI: 0.63-0.85) but not for hydrophilic statin users (HR 1.17, 95% CI: 0.82-1.68). Furthermore, statin users exhibited a lower risk of breast cancer mortality (HR 0.80, 95% CI: 0.66-0.96) but all-cause mortality (HR 0.82, 95% CI: 0.66-1.02) was comparable among both groups of patients. Conversely, lipophilic statins demonstrated a reduction in both all-cause mortality (HR 0.84, 95% CI: 0.75-0.93) and breast cancer mortality (HR 0.85, 95% CI: 0.74-0.99) compared to non-statin users.

CONCLUSION

Among patients with breast cancer, statin use post-diagnosis decreases the risk of breast cancer recurrence and breast cancer mortality. Furthermore, lipophilic statins exhibit an additional advantage of reduction in all-cause mortality.PROSPERO registration: CRD42022362011.