Comparative effects of torasemide and furosemide on gap junction proteins and cardiac fibrosis in a rat model of dilated cardiomyopathy

READY: relative efficacy of loop diuretics in patients with chronic systolic heart failure-a systematic review and network meta-analysis of randomised trials

The majority of patients with chronic heart failure (HF) receive long-term treatment with loop diuretics. The comparative effectiveness of different loop diuretics is unknown. We searched PubMed, clinicaltrials.gov , the Cochrane Central Register of Controlled Trials and the European Union Clinical Trials Register for randomised clinical trials exploring the efficacy of the loop diuretics azosemide, bumetanide, furosemide or torasemide in patients with HF. Comparators included placebo, standard medical care or any other active treatment. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular mortality, HF-related hospitalisation and any combined endpoint thereof. Hypokalaemia and acute renal failure were defined as additional safety endpoints. Evidence was synthesised using network meta-analysis (NMA). Thirty-four trials reporting on 2647 patients were included. The overall quality of evidence was rated as moderate. NMA demonstrated no significant differences between loop diuretics with respect to all-cause mortality, cardiovascular mortality or hypokalaemia. In contrast, torasemide ranked best in terms of HF hospitalisation, and there was a trend towards benefits with torasemide with regard to occurrence of acute renal failure. Sensitivity analyses excluding trials with a follow-up < 6 months, trials with a cross-over design and those including < 25 patients confirmed the main results. We found no significant superiority of either loop diuretic with respect to mortality and safety endpoints. However, clinicians may prefer torasemide, as it was associated with fewer HF-related hospitalisations.

Comparative effectiveness of loop diuretics on mortality in the treatment of patients with chronic heart failure - A multicenter propensity score matched analysis

BACKGROUND

Loop diuretics are given to the majority of patients with chronic heart failure (HF). Whether the different pharmacological properties of the three guideline-recommended loop diuretics result in differential effects on survival is unknown.

METHODS

6293 patients with chronic HF using either bumetanide, furosemide or torasemide were identified in three European HF registries. Patients were individually matched on both the respective propensity scores for receipt of the individual drug and dose-equivalents thereof.

RESULTS

During a follow-up of 35,038 patient-years, 652 (53.7%), 2179 (51.9%), and 268 (30.4%) patients died amongst those prescribed bumetanide, furosemide, and torasemide, respectively. In univariable analyses of the general sample, bumetanide and furosemide were both associated with higher mortality as compared with torasemide treatment (HR 1.50, 95% CI 1.31-1.73, p < 0.001, and HR 1.34, CI 1.18-1.52, p < 0.001, respectively). Mortality was higher in bumetanide users when compared to furosemide users (HR 1.11, 95% CI 1.02-1.20, p = 0.01). However, there was no significant association between loop diuretic choice and all-cause mortality in any of the matched samples (bumetanide vs. furosemide, HR 1.03, 95% CI 0.93-1.14, p = 0.53; bumetanide vs. torasemide, HR 0.98, 95% CI 0.78-1.24, p = 0.89; furosemide vs. torasemide, HR 1.02, 95% CI 0.84-1.24, p = 0.82). The results were confirmed in subgroup analyses with respect to age, sex, left ventricular ejection fraction, NYHA functional class, cause of HF, rhythm, and systolic blood pressure.

CONCLUSIONS

In patients with HF, mortality is not affected by the choice of individual loop diuretics.

Comparative evaluation of torasemide and spironolactone on adverse cardiac remodeling in a rat model of dilated cardiomyopathy

BACKGROUND

Chronic heart failure (CHF) involves fluid retention and volume overload, leading to impaired cardiac function. In these conditions, diuretic agents are most commonly used to treat edema and thereby reducing the volume load on the failing heart. There are several other beneficial effects of diuretics apart from their action on urinary excretion.

METHODS

To identify the effects of diuretic agents on adverse cardiac remodeling in CHF, this study was carried out, where we have compared the effects of torasemide and spironolactone in a rat model of dilated cardiomyopathy induced by porcine cardiac myosin-mediated experimental autoimmune myocarditis.

RESULTS

Cardiac protein expression levels of inflammation, endoplasmic reticulum stress, and fibrosis markers were upregulated in the hearts of CHF rats, while treatment with either torasemide or spironolactone has downregulated their expression. The effect produced by spironolactone on cardiac fibrosis markers was comparably lesser than torasemide. Further, immunohistochemical analysis and histopathological studies have provided evidence to confirm the beneficial effects of these drugs on adverse cardiac remodeling in rats with CHF.

CONCLUSION

Torasemide treatment has benefits against adverse cardiac remodeling in CHF rats, which was better than the protection offered by spironolactone.