CHF is the predominant reason of mortality and hospitalization worldwide, therefore, improving the length and quality of life remains the most important goal that must be taken into account when developing new drugs. To provide a perspective on the relative survival benefit of the promising new drug classes for CHF, we conducted a network meta-analysis of 33 trials to estimate the relative efficacy of the NTDs in reducing mortality, HF hospitalization rate, and adverse events. The results of this network meta-analysis may provide evidence to support the recommendation of superior drugs for treatment of CHF.
The results of our network meta-analysis did not indicate a significant superiority of one of the tested NTDs in terms of reducing all-cause mortality, composite outcome of CV death or HF hospitalization, and HF hospitalization alone. Although SGLT2 inhibitors performed well when compared to SOC for all above outcomes, these benefits were not sufficient enough to make significant differences with other drug classes. For CV death, additional survival benefits were found in ARNI over ivabradine and CMAs, and in SGLT2 inhibitors over CMAs, indicating that ARNI and SGLT2 inhibitors were the most efficacious treatment to reduce CV mortality. And there were no significant differences between these 2 superior drug classes. For safety outcomes, SGLT2 inhibitors were associated with additional reduction for serious adverse events compared to ivabradine and CMAs, while ivabradine was associated with an increased risk for discontinuation due to adverse events compared to ARNI and SOC. Despite the mostly non-significant differences, treatments with SGLT2 inhibitors maybe preferred over therapies with other new drug classes based on their association with lower mortality and their favorable serious adverse events profile as well as the highest SUCRA scores in most outcomes. ARNI followed, for the lowest CV mortality and the second highest SUCRA scores in most outcomes.
Previous studies have demonstrated an association between SGLT2 inhibition and reduction of mortality and HF hospitalization rate in patients with diabetes53,54. Moreover, in subsequent trials, similar findings were observed in patients with established heart failure with or without diabetes. Specifically, Empagliflozin and Sotagliflozin displayed a superiority over SOC both in HFrHF and HFpHF32,33,37, while Dapagliflozin demonstrated its benefits only in HFrEF31,34,36 (trials assessing the effects of Dapagliflozin on HFpEF were ongoing and their data were unavailable). A recent meta-analysis found that the benefits of SGLT2 inhibitors were primarily driven by reduction on HF hospitalization rate, while their effects on CV mortality were modest55. Our results seem to be in line with these findings. The magnitude of the reduction in HF hospitalization rate (HR 0.75, 95%CI 0.64 to 0.88) was much greater than the reduction in CV mortality (HR 0.87, 95%CI 0.77 to 0.98). Accordingly, SGLT2 inhibitors were most likely to rank third best in reducing CV mortality, slightly inferior to ARNI and non-steroidal MRA. Such results may provide reference for clinical therapeutic decision for heart failure.
Sacubitril/valsartan, the only ARNI, was developed to combine neprilysin inhibitor sacubitril and angiotensin receptor blocker valsartan together with a design to minimize the risk of adverse effects56. The PARADIGM-HF and PARAGON-HF trials have demonstrated the superiority of ARNI over SOC in HFrEF and HFpEF respectively10,11. In 2016 AHA/ACC guidelines, Sacubitril/valsartan was recommended for patient with chronic HFrEF to reduce morbidity and mortality13. In this analysis, Sacubitril/valsartan was found to be a good alternative in CHF, especially for reducing CV mortality. Sacubitril/valsartan shared partially overlapping mechanisms with SGC stimulators in increasing the level of cyclic guanosine monophosphate through natriuretic peptides enhancement57. Howerver, SGC stimulators did not outperform SOC as expected in treating heart failure. Among the 3 included SGC stimulators (Riociguat, praliciguat and vericiguat), only vericiguat was investigated in a phase 3 trial with a large sample size. The phase 3 VICTORIA trial demonstrated vericiguat as a promising treatment for heart failure49, indicating more dedicated trials for vericiguat were needed to collect comprehensive information.
Ivabradine is a novel heart rate lowering drug that specifically inhibits the cardiac If channels in the sinus node. The SHIFT and BEAUTIFUL trials have demonstrated that ivabradine can translate the reduction effect of heart rate into beneficial effects for improving the prognosis of heart failure12,40. However, these beneficial effects were limited to the patients with heart rate of 70 bpm or greater at baseline. In this analysis, when patients baseline characteristics were set to be in consistency with other drugs’ trials, ivabradine showed no benefits on the prognostic in heart failure, except for the outcome of “HF hospitalization”. An increased risk of discontinuation due to adverse events for Ivabradine was also observed in this analysis, the usage in partially inappropriate population (HR < 70 bmp) might explain why the acceptability of Ivabradine was lower.
Omecamtiv mecarbil was a first-in-class cardiac myosin activator, which selectively binding to cardiac myosin to augment cardiac contractility, thus improving myocardial function in patients with CHF8. Recently, the GALACTIC-HF trial failed to get expected results, no improvement on CV mortality and all-cause mortality was observed in Omecamtiv mecarbil15. In this analysis, Omecamtiv mecarbil, included as the only CMA, was not associated with any benefits in treating heart failure. For the outcome of CV mortality, we found an inferior performance of Omecamtiv mecarbil when compared to ARNI and SGLT2 inhibitors, which may herald a lower priority of this drug when considering the CV mortality as an important factor in clinical decision.
Due to lacking of large-sample multicenter trials, the available evidence from non-steroidal MRA trials seemed not strong enough. Despite all this, the existing data suggested that non-steroidal MRA may have therapeutic potential for some specific outcomes, especially for CV mortality and adverse events. The phase 3 trials FINEARTS-HF and JPRN-UMIN000037111 were now ongoing to investigated the effect of Finerenone and Esaxerenone in heart failure, respectively, which may provide more clear evidences.
To date, no head-to-head trial has directly compared the relative effects of these NTDs in heart failure. Our analysis may be a step forward in this direction with the help of the network meta-analysis statistical approach to conduct indirect comparison. The results may provide a reference for subsequent clinical practice and trial design. In this analysis, SGLT2 inhibitors were found to have the best SUCRA scores for most outcomes, indicating SGLT2 inhibitors may be the most promising treatment option for heart failure. It is important to stress that our findings are hypothesis generating, so more practical evidence is needed. Recently, FDA approved the use of dapagliflozin for treatment of HF, and it is anticipated that dapagliflozin will be added to guideline-directed medical therapy for HF in 2021 ACA/AHA heart failure guideline58. It is envisioned that more trials, including head-to-head trials, will be designed to investigate the role of SGLT2 inhibitors in patients with heart failure. Such trials could assist the determine of better therapeutic treatment algorithms, tailored to the appropriate population for each drug.
Limitations
This analysis has several limitations. First, we did not evaluate the consistency between direct and indirect evidences because there is no trials directly comparing these drug therapies, all the evidences were based on indirect comparisons. Second, the number of included trials investigating CMA was relatively small, so as the number of included patients in non-steroidal MRA trials, resulting in limited statistical power. Third, we did not evaluate the relative clinical efficacy and safety of individual drug types as well as individual doses. In our analysis, there is only 1 drug in most drug classes, except for SGLT2 inhibitors (containing dapagliflozin, empagliflozin and sotagliflozin) and SGC stimulators (containing Riociguat, Praliciguat and Vericiguat), and their between-study heterogeneity is low, suggesting little variability of treatment effects exist within drug classes. Fourth, the trials enrolled different patients with a broad spectrum of heart failure, as well as different percentages of SOC drugs. Although the heterogeneity between study populations still allowed a reliable comparisons, more subgroup analysis should be conducted in future studies.