Effects of medical therapy, transcatheter intervention, and surgery on outcomes of patients with functional mitral regurgitation: a systematic review and network meta-analysis

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.

Background

Functional mitral regurgitation (FMR) is the most common valvular heart disease worldwide. Despite recent major trials, the relative efficacy between medical therapy, transcatheter intervention, and surgery for the treatment of FMR remains poorly understood.

Purpose

We performed a systematic review and network meta-analysis of all published randomised controlled trials (RCTs) and observational studies to compare the efficacy between medical therapy, transcatheter intervention, and surgery on the clinical outcomes of patients with FMR.

Methods

Four electronic databases (PubMed, EMBASE, SCOPUS, and the Cochrane Library) were searched from inception to March 13, 2022, for studies reporting clinical outcomes in patients with FMR and comparing the efficacy between either medical therapy, transcatheter intervention, or surgery. Frequentist network meta-analysis models were utilised to summarise the studies. This study was registered in the International Prospective Register of Systematic Reviews.

Results

10 articles were included in the analysis, comprising a combined cohort of 1,981 patients. Network meta-analysis demonstrated that compared to medical therapy, transcatheter intervention achieved a lower relative risk in the composites of all-cause mortality (risk ratio [RR]: 0.43; 95% confidence interval [CI] 0.22-0.82) and mitral regurgitation (MR) severity grade ≥3+ (RR: 0.06; 95% CI 0.01-0.42). Compared to surgery, transcatheter intervention achieved a lower relative risk in the composites of cardiovascular death (RR: 0.36; 95% CI 0.17-0.75) and MR severity grade ≥3+ (RR: 0.25; 95% CI 0.09-0.70) and higher relative risk in the composite of heart failure hospitalisation (RR: 2.94; 95% CI 1.26-6.82). Compared to medical therapy, surgery achieved a higher relative risk in the composite of cardiovascular death (RR: 2.54; 95% CI 1.18-5.47) and lower relative risks in the composites of all-cause mortality (RR: 0.56; 95% CI 0.34-0.91) and heart failure hospitalisation (RR: 0.28; 95% CI 0.13-0.61).

Conclusion

Medical therapy, transcatheter intervention, and surgery in patients with FMR displayed differing effects on the various clinical outcomes. Further head-to-head trials are required to better understand the optimal treatment modality in this population.

Association of left atrial ejection fraction and cardiovascular outcomes in Asian patients with hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme

Background

The optimal method of risk stratification of hyp­ertrophic cardiomyopathy (HCM) patients, especially in the Asian population, is unknown. Left atrial ejection fraction (LAEF) is an emerging risk marker for cardiovascular outcomes. This study aimed to investigate whether LAEF was associated with cardiovascular outcomes in Asian patients with HCM.

Methods

This was a retrospective cohort study performed in a tertiary academic centre involving 291 consecutive patients diagnosed with HCM between 2010 and 2017. We collected the relevant clinical characteristics of these patients and retrospectively analysed the index transthoracic echocardiograms for novel left atrial indices including LAEF. We obtained the maximum (LAVmax) and minimum left atrial volumes (LAVmin) using the biplane method of disks in apical 4- and 2-chamber views. LAEF was derived by dividing the difference between LAVmax and LAVmin by LAVmax. We assessed the patients for outcomes of (1) heart failure requiring admission, and (2) a composite of adverse outcomes including all-cause mortality, ventricular tachycardia / ventricular fibrillation (VT/VF) events, appropriate device therapy if an implantable cardioverter defibrillator (ICD) was implanted, stroke and heart failure hospitalization.

Results

The patients had a mean age of 59.0 ± 16.7 years-old at diagnosis and had a male preponderance (71.2%). The most common comorbidities were hypertension, diabetes mellitus and ischemic heart disease. On univariable logistic regression analysis, maximum and minimum left atrial volume index (LAVI) as well as LAEF showed a significant association with heart failure and the predefined composite outcome. On Cox regression analysis adjusting for variables of age, sex, left ventricular ejection fraction (LVEF), left ventricular maximal wall thickness >30mm, significant left ventricular outflow tract (LVOT) gradient of > 30mmHg and more than moderate mitral regurgitation, maximum and minimum LAVI as well as LAEF retained an association with heart failure admission but only minimum LAVI and LAEF were associated with the composite outcome [(OR 0.019, 95% CI 0.02-0.230, p=0.002), (OR 0.226, 95% CI 0.053-0.960, p=0.044), (OR 1.030, 95% CI 1.016-1.045, p<0.001), and (OR 1.016, 95% CI 1.005-1.026, p=0.004) respectively].

Conclusion

LAEF was an independently associated with congestive heart failure as well as a composite of adverse outcomes in Asian patients with HCM.

Natural history of functional mitral regurgitation: a systematic review and individual patient data meta-analysis

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.

Background

Functional mitral regurgitation (FMR) precipitates a vicious cycle of left ventricular volume overload and remodelling, leading to perpetual worsening of FMR and left ventricular dysfunction, with a resultant poor prognosis. However, there is a lack of conclusive data on the natural progression of FMR in patients who do not undergo valvular intervention.

Purpose

We performed a one-stage meta-analysis on reconstructed individual patient data (IPD) to elucidate the natural history of FMR.

Methods

Four databases (PubMed, Embase, Scopus, Cochrane) were searched for randomised controlled trials or cohorts, published from inception to March 13, 2022, reporting clinical outcomes in patients with FMR not receiving valvular intervention. IPD meta-analysis, as the gold standard approach for evidence synthesis, was performed with reconstructed IPD obtained from the survival curves reported in the included studies. Pooled survival estimates were derived. Quality assessment of included studies was conducted using the Cochrane risk-of-bias tool and Newcastle Ottawa Scale. This study was registered on the International Prospective Register of Systematic Reviews.

Results

A total of five studies were included, comprising a total cohort of 691 patients with FMR who did not undergo valvular intervention. The mean age of the cohort was 72.4 years (95% CI 67.6 to 77.1) and the proportion of males was 61.1% (95% CI 43.8 to 76.0). All-cause mortality was analysed over a follow-up duration of five years, while hospitalisation for heart failure, cardiovascular death, and the composite of all-cause mortality and hospitalisation for heart failure were analysed over a follow-up duration of three years. The probability of survival of patients with FMR without intervention was 79.4% (95% CI 76.2 to 82.3), 50.9% (95% CI 46.6 to 55.1), and 39.6% (95% CI 33.1 to 46.0) at one, three, and five years respectively. The probability of survival free from the composite of all-cause mortality and hospitalisation for heart failure was 51.3% (95% CI 46.8 to 55.6) and 12.0% (95% CI 8.9 to 15.7) at one year and three years respectively. The probability of survival free from hospitalisation for heart failure was 58.3% (95% CI 54.0 to 62.3) and 19.7% (95% CI 16.0 to 23.7) at one and three years respectively. The probability of survival free from cardiovascular death was 75.4% (95% CI 68.9 to 80.8) and 45.6% (95% CI 29.1 to 60.7) at one and three years respectively. All included studies were of low to moderate risk of bias.

Conclusion

FMR in the absence of valvular intervention is associated with poor survival and cardiovascular outcomes. Further research should focus on the role of interventions to mitigate its poor prognosis.

Genotype-guided versus traditional clinical dosing of warfarin in patients of Asian ancestry: a randomized controlled trial

BACKGROUND

Genotype-guided warfarin dosing has been shown in some randomized trials to improve anticoagulation outcomes in individuals of European ancestry, yet its utility in Asian patients remains unresolved.

METHODS

An open-label, non-inferiority, 1:1 randomized trial was conducted at three academic hospitals in South East Asia, involving 322 ethnically diverse patients newly indicated for warfarin (NCT00700895). Clinical follow-up was 90 days. The primary efficacy measure was the number of dose titrations within the first 2 weeks of therapy, with a mean non-inferiority margin of 0.5 over the first 14 days of therapy.

RESULTS

Among 322 randomized patients, 269 were evaluable for the primary endpoint. Compared with traditional dosing, the genotype-guided group required fewer dose titrations during the first 2 weeks (1.77 vs. 2.93, difference -1.16, 90% CI -1.48 to -0.84, P < 0.001 for both non-inferiority and superiority). The percentage of time within the therapeutic range over 3 months and median time to stable international normalized ratio (INR) did not differ between the genotype-guided and traditional dosing groups. The frequency of dose titrations (incidence rate ratio 0.76, 95% CI 0.67 to 0.86, P = 0.001), but not frequency of INR measurements, was lower at 1, 2, and 3 months in the genotype-guided group. The proportions of patients who experienced minor or major bleeding, recurrent venous thromboembolism, or out-of-range INR did not differ between both arms. For predicting maintenance doses, the pharmacogenetic algorithm achieved an R² = 42.4% (P < 0.001) and mean percentage error of -7.4%.

CONCLUSIONS

Among Asian adults commencing warfarin therapy, a pharmacogenetic algorithm meets criteria for both non-inferiority and superiority in reducing dose titrations compared with a traditional dosing approach, and performs well in prediction of actual maintenance doses. These findings imply that clinicians may consider applying a pharmacogenetic algorithm to personalize initial warfarin dosages in Asian patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00700895 . Registered on June 19, 2008.

Refractory hypoxaemia following inferior ST-segment elevation myocardial infarction: case report of an unusual complication and review of treatment strategies

Right ventricular (RV) infarction is not an uncommon complication of acute left ventricular infarction. It has been established that RV dysfunction post myocardial infarction (MI) is associated with increased mortality and morbidity. When RV infarction occurs in a patient with previously dormant patent foramen ovale (PFO), an unusual presentation of persistent refractory hypoxaemia ensues. We present a case of new RV infarction in a patient with underlying ischaemic cardiomyopathy, which was complicated by acute right-to-left shunting through the PFO. He was treated with percutaneous coronary intervention (PCI) and subsequent percutaneous PFO closure. We will also review the existing literature with regards to diagnostic and management strategies for patients with this unusual sequelae of MI.

ReoPro Observational Registry (RAPOR): insights from the multicentre use of abciximab in Asia

INTRODUCTION

The pattern of use of abciximab in real-life clinical patients undergoing percutaneous coronary intervention (PCI) in 11 high-volume centres in Singapore, Malaysia, Thailand, Philippines, India, Pakistan and Korea was prospectively examined.

METHODS

These centres enrolled 224 consecutive patients over eight months to receive abciximab during PCI for the study. The cohort consisted of 82.1 percent males, with mean age of 55 (+/- 11) years and mean weight of 67 (+/- 17) kg.

RESULTS

The use of abciximab during PCI ranged between 6.2 percent and 21.6 percent. The indications for the use of abciximab were: acute coronary syndromes (34.3 percent), complex coronary lesions (17.9 percent) and multivessel PCI (17.7 percent). Based on a risk scoring system devised for this registry, majority (60.0 percent) of the patients was considered high risk when abciximab was used. Among the patients enrolled, 36.6 percent received abciximab as a "bail-out". The overall in-hospital ischaemic event rates were low at 4.0 percent. The complication rates included major bleeding 0.7 percent, thrombocytopenia 2.7 percent and need for blood transfusion 2.8 percent. There was a trend towards a higher incidence of in-hospital non-Q myocardial infarction in the "bail-out" group (2.1 percent versus 7.3 percent, p-value equals 0.07).

CONCLUSION

Abxicimab was uncommonly used among patients (9.4 percent) undergoing PCI in this Asian region, with the operators reserving it mainly for high-risk patients.