Mineralocorticoid receptor antagonists in patients with acute myocardial infarction - A systematic review and meta-analysis of randomized trials

Adverse Effects of Aldosterone: Beyond Blood Pressure

Aldosterone is a steroid hormone that primarily acts through activation of the mineralocorticoid receptor (MR), a nuclear receptor responsible for downstream genomic regulation. Classically, activation of the MR in the renal tubular epithelium is responsible for sodium retention and volume expansion, raising systemic blood pressure. However, activation of the MR across a wide distribution of tissue types has been implicated in multiple adverse consequences for cardiovascular, cerebrovascular, renal, and metabolic disease, independent of blood pressure alone. Primary aldosteronism, heart failure, and chronic kidney disease are states of excessive aldosterone production and MR activity where targeting MR activation has had clinical benefits out of proportion to blood pressure lowering. The growing list of established and emerging therapies that target aldosterone and MR activation may provide new opportunities to improve clinical outcomes and enhance cardiovascular and renal health.

Patterns of left ventricular remodeling post-myocardial infarction, determinants, and outcome

AIM

Left ventricular remodeling (LVR) after myocardial infarction (MI) can lead to heart failure, arrhythmia, and death. We aim to describe adverse LVR patterns at 6 months post-MI and their relationships with subsequent outcomes and to determine baseline.

METHODS AND RESULTS

A multicenter cohort of 410 patients (median age 57 years, 87% male) with reperfused MI and at least 3 akinetic LV segments on admission was analyzed. All patients had transthoracic echocardiography performed 4 days and 6 months post-MI, and 214 also had cardiac magnetic resonance imaging performed on day 4. To predict LVR, machine learning methods were employed in order to handle many variables, some of which may have complex interactions. Six months post-MI, echocardiographic increases in LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were 14.1% [interquartile range 0.0, 32.0], 5.0% [- 14.0, 25.8], and 8.7% [0.0, 19.4], respectively. At 6 months, ≥ 15% or 20% increases in LVEDV were observed in 49% and 42% of patients, respectively, and 37% had an LVEF < 50%. The rate of death or new-onset HF at the end of 5-year follow-up was 8.8%. Baseline variables associated with adverse LVR were determined best by random forest analysis and included stroke volume, stroke work, necrosis size, LVEDV, LVEF, and LV afterload, the latter assessed by Ea or Ea/Ees. In contrast, baseline clinical and biological characteristics were poorly predictive of LVR. After adjustment for predictive baseline variables, LV dilation > 20% and 6-month LVEF < 50% were significantly associated with the risk of death and/or heart failure: hazard ratio (HR) 2.12 (95% confidence interval (CI) 1.05-4.43; p = 0.04) and HR 2.68 (95% CI 1.20-6.00; p = 0.016) respectively.

CONCLUSION

Despite early reperfusion and cardioprotective therapy, adverse LVR remains frequent after acute MI and is associated with a risk of death and HF. A machine learning approach identified and prioritized early variables that are associated with adverse LVR and which were mainly hemodynamic, combining LV volumes, estimates of systolic function, and afterload.

Aldosterone and cardiovascular diseases

Aldosterone's role in the kidney and its pathophysiologic actions in hypertension are well known. However, its role or that of its receptor [minieralocorticoid receptor (MR)] in other cardiovascular (CV) disease are less well described. To identify their potential roles in six CV conditions (heart failure, myocardial infarction, atrial fibrillation, stroke, atherosclerosis, and thrombosis), we assessed these associations in the following four areas: (i) mechanistic studies in rodents and humans; (ii) pre-clinical studies of MR antagonists; (iii) clinical trials of MR antagonists; and (iv) genetics. The data were acquired from an online search of the National Library of Medicine using the PubMed search engine from January 2011 through June 2021. There were 3702 publications identified with 200 publications meeting our inclusion and exclusion criteria. Data strongly supported an association between heart failure and dysregulated aldosterone/MR. This association is not surprising given aldosterone/MR's prominent role in regulating sodium/volume homeostasis. Atrial fibrillation and myocardial infarction are also associated with dysregulated aldosterone/MR, but less strongly. For the most part, the data were insufficient to determine whether there was a relationship between atherosclerosis, stroke, or thrombosis and aldosterone/MR dysregulation. This review clearly documented an expanding role for aldosterone/MR's dysregulation in CV diseases beyond hypertension. How expansive it might be is limited by the currently available data. It is anticipated that with an increased focus on aldosterone/MR's potential roles in these diseases, additional clinical and pre-clinical data will clarify these relationships, thereby, opening approaches to use modulators of aldosterone/MR's action to more precisely treat these CV conditions.

An overview of mineralocorticoid receptor antagonists as a treatment option for patients with heart failure: the current state-of-the-art and future outlook

INTRODUCTION

Mineralocorticoid receptor antagonists (MRAs) improve cardiovascular outcomes in patients with heart failure. These benefits of MRAs vary in different heart failure populations based on left ventricular ejection fraction and associated comorbidities.

AREAS COVERED

We define the pharmacologic properties of MRAs and the pathophysiological rationale for their utility in heart failure. We outline the current literature on the use of MRAs in different heart failure populations, including reduced and preserved ejection fraction (HFrEF/ HFpEF), and acute heart failure decompensation. Finally, we describe the limitations of currently available data and propose future directions of study.

EXPERT OPINION

While there is strong evidence supporting the use of MRAs in HFrEF, evidence in patients with HFpEF or acute heart failure is less definitive. Comorbidities such as obesity or atrial fibrillation could be clinical modifiers of the response to MRAs and potentially alter the risk/benefit ratio in these subpopulations. Emerging evidence for new non-steroidal MRAs reveal promising preliminary results that, if confirmed in large randomized clinical trials, could favor a change in clinical practice.

Left Ventricular Remodeling after Myocardial Infarction: From Physiopathology to Treatment

Myocardial infarction (MI) is the leading cause of death and morbidity worldwide, with an incidence relatively high in developed countries and rapidly growing in developing countries. The most common cause of MI is the rupture of an atherosclerotic plaque with subsequent thrombotic occlusion in the coronary circulation. This causes cardiomyocyte death and myocardial necrosis, with subsequent inflammation and fibrosis. Current therapies aim to restore coronary flow by thrombus dissolution with pharmaceutical treatment and/or intravascular stent implantation and to counteract neurohormonal activation. Despite these therapies, the injury caused by myocardial ischemia leads to left ventricular remodeling; this process involves changes in cardiac geometry, dimension and function and eventually progression to heart failure (HF). This review describes the pathophysiological mechanism that leads to cardiac remodeling and the therapeutic strategies with a role in slowing the progression of remodeling and improving cardiac structure and function.

Spironolactone Improves the All-Cause Mortality and Re-Hospitalization Rates in Acute Myocardial Infarction with Chronic Kidney Disease Patients

Background: Mineralocorticoid receptor antagonists (MRA) improve outcomes in chronic kidney disease (CKD) and acute myocardial infarction (AMI) patients. However, the lack of evidence regarding long-term clinical outcomes in the use of MRA, including spironolactone, in patients with AMI combined with CKD.

Objectives: This study aimed to investigate whether spironolactone could significantly reduce the risk of all-cause mortality and re-admission in patients with AMI and CKD.

Methods: In this single center, observational, retrospective, registry based clinical study, a total of 2,465 AMI patients were initially screened; after excluding patients with estimated glomerular filtration rate more than 60 ml/min/1.73 m², 360 patients in the standard treatment group and 200 patients in the spironolactone group met the criteria. All enrolled patients follow-up for 30 months. The primary outcomes were all-cause mortality and re-admission. The key safety outcome was hyperkalemia rates during the 30 months follow-up period.

Results: 160 (44.4%) and 41 (20.5%) patients in the standard treatment and spironolactone groups died, respectively [hazard ratio (HR): 0.389; 95% confidence interval (CI): 0.276–0.548; p < 0.001]. Re-admission occurred in 217 (60.3%) and 95 (47.5%) patients in the standard treatment and spironolactone groups, respectively (HR: 0.664; 95% CI: 0.522–0.846; p = 0.004). The spironolactone group was divided into two based on the daily dose, low dose group (no more than 40 mg) and high dose group (more than 40 mg); the differences in the mortality rate between low dose group (16.7%) and the standard treatment group (44.4%) (HR: 0.309; 95% CI: 0.228–0.418; p < 0.001) and high dose group (34.1%) (HR: 0.429; 95% CI: 0.199–0.925; p = 0.007) were significant. The differences in re-hospitalization rate between low dose group (43.6%) and the standard treatment group (60.3%) (HR: 0.583; 95% CI: 0.457–0.744; p < 0.001) and high dose group (61.4%) (HR: 0.551; 95% CI: 0.326–0.930; p = 0.007) was significant. Hyperkalemia occurred in 18 (9.0%) and 18 (5.0%) patients in the spironolactone group and standard treatment group, respectively (HR: 1.879; 95% CI: 0.954–3.700; p = 0.068). Whereas, Hyperkalemia occurred in high dose group (20.5%) significantly more often than in the standard treatment group (p < 0.001) and low dose group (5.8%) (p = 0.003).

Conclusion: Using MRA, such as spironolactone, may substantially reduce the risk of both all-cause mortality and re-admission in patients with AMI and CKD; the use of low-dose spironolactone has the best efficacy and safety. However, this was a relatively small sample size, single center, observational, retrospective, registry based clinical study and further prospective evaluation in adequately powered randomized trials were needed before further use of spironolactone in AMI with CKD population.

Pre- and Post-Conditioning of the Heart: An Overview of Cardioprotective Signaling Pathways

Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and pharmacological conditioning related to the heart. In addition, we reviewed the cardioprotective signaling pathways and therapeutic agents involved in the above-mentioned processes, aiming to provide a comprehensive evaluation of the advancements in the field. The advancements made over the last decades cannot be ignored and with the exponential growth in techniques and applications. The future of pre- and post-conditioning is promising.

Mineralocorticoid receptor antagonist pre-treatment and early post-treatment to minimize reperfusion injury after ST-elevation myocardial infarction: The MINIMIZE STEMI trial

Background

Mineralocorticoid receptor antagonist (MRA) therapy has been shown to prevent adverse left ventricular (LV) remodeling in ST-segment elevation myocardial infarction (STEMI) patients with heart failure. Whether initiating MRA therapy prior to primary percutaneous coronary intervention (PPCI) accrues additional benefit of reducing myocardial infarct size and preventing adverse LV remodeling is not known. We aimed to investigate whether MRA therapy initiated prior to reperfusion reduces myocardial infarct (MI) size and prevents adverse LV remodeling in STEMI patients.

Methods

STEMI patients presenting within 12 hours and with a proximal coronary artery occlusion with Thrombolysis In Myocardial Infarction flow grade 0 were consented and randomized to either an intravenous bolus of potassium canrenoate, followed by oral spironolactone for 3 months or matching placebo. The primary endpoint was MI size by cardiovascular magnetic resonance at 3 months.

Results

Sixty-seven patients completed the study. There was no significant difference in the final MI size at 3 months between the 2 groups (placebo: 17 ± 11%, MRA: 16 ± 10%, P = .574). There was also no difference in acute MI size (26 ± 16% versus 23 ± 14%, P = .425) or myocardial salvage (26 ± 12% versus 24 ± 8%, P = .456). At follow-up, there was a trend towards an improvement in LVEF (placebo: 49 ± 8%, MRA: 54 ± 11%, P = .053), and the MRA group had significantly greater percentage decrease in LVEDV (mean difference: −12.2 (95% CI −20.3 to −4.4)%, P = .003) and LVESV (mean difference: −18.2 (95% CI −30.1 to −6.3)%, P = .003).

Conclusion

This pilot study showed no benefit of MRA therapy in reducing MI size in STEMI patients when initiated prior to reperfusion, but there was an improvement in LV remodeling at 3 months. Adequately powered studies are warranted to confirm these findings.

Aldosterone Antagonists Reduce the Risk of Cardiovascular Mortality in Dialysis Patients: A Meta-Analysis

Background and Purpose. Cardiovascular disease is the major cause of death in dialysis patients. Although aldosterone antagonists were considered a treatment for severe heart failure patients to reduce cardiac mortality, whether treating patients undergoing maintenance dialysis with aldosterone antagonists could reduce the risk of cardiocerebrovascular (CCV) remains unclear. We aim to systematically assess the efficacy and tolerability of the addition of aldosterone antagonists to conventional therapy in patients undergoing maintenance dialysis. Materials and Methods. We searched PubMed, EMBASE, the Cochrane Library, the Chinese Biomedical Literature Database (CBM), and the China National Knowledge Infrastructure (CNKI) for relevant articles. The primary endpoint of interest was CCV mortality. The secondary endpoints were all-cause mortality, left ventricular mass index (LVMI), and left ventricular ejection fraction (LVEF). Publication bias was evaluated using funnel plots and Egger's test. The meta-analysis was performed using Review Manager software version 5.3. Results. This analysis included 10 randomized controlled trials (RCTs) with 1172 total chronic dialysis patients. The use of aldosterone antagonists in the dialysis population resulted in a marked reduction in CCV mortality (RR 0.42, 95% CI 0.26-0.65, P=0.0002) and all-cause mortality (RR0.46, 95%CI 0.32-0.66, P<0.0001). The LVEF was improved by treatment with aldosterone antagonists (WMD 6.35%, P<0.00001). Moreover, aldosterone antagonists decreased the LVMI (WMD -8.69 g/m², P=0.0006), whereas aldosterone antagonists increased the occurrence of hyperkalemia (RR1.70, 95%CI 1-2.88, P=0.05) and gynecomastia (RR 8.01, 95% CI 2.44- 26.27, P=0.0006). Conclusions. Addition of aldosterone antagonists to conventional treatment in chronic dialysis patients may reduce CCV mortality, improve cardiac function, and simultaneously decrease LVMI.

Mechanisms underlying the cardio-protection of total ginsenosides against myocardial ischemia in rats in vivo and in vitro: Possible involvement of L-type Ca2+ channels, contractility and Ca2+ homeostasis

Here we aimed to observe the effects of total ginsenosides (TG) against isoproterenol (ISO) induced myocardial ischemia (MI) and to explore its underlying mechanisms based on L-type Ca²⁺ current (I_Ca-L), intracellular Ca²⁺ ([Ca²⁺]_i) and contraction in isolated rat myocytes. Rat model of MI was induced by subcutaneously injection of ISO (85 mg/kg) for 2 consecutive days. J-point elevation, heart rate, serum levels of creatine kinase (CK) and lactated dehydrogenase (LDH), and heart morphology changes were observed. Influences of TG on I_Ca-L, [Ca²⁺]_i and contraction in isolated rat myocytes were observed by the patch-clamp technique and IonOptix detection system. TG significantly reduced J-point elevation, heart rate, serum levels of CK and LDH, and improved heart pathologic morphology. TG decreased I_Ca-L in concentration-dependent manner with a half-maximal inhibitory concentration (IC₅₀) of 31.65 μg/mL. TG (300 μg/mL) decreased I_Ca-L of normal and ischemic ventricular myocytes by 64.33 ± 1.28% and 61.29 ± 1.38% respectively. At 30 μg/mL, TG reduced Ca²⁺ transient by 21.67 ± 0.94% and cell shortening by 38.43 ± 6.49%. This study showed that TG displayed cardioprotective effects on ISO-induced MI rats and the underlying mechanisms may be related to inhibition of I_Ca-L, damping of [Ca²⁺]_i and decrease of contractility.

Efficacy of mineralocorticoid receptor antagonists in postmyocardial infarction patients with or without left ventricular dysfunction: A meta-analysis of randomized controlled trials

BACKGROUND

There is heated debate about the benefits of using mineralocorticoid receptor antagonists (MRAs) in addition to standard therapy in patients admitted for myocardial infarction (MI) with or without left ventricular dysfunction (LVD).

METHODS

Randomized controlled trials (RCTs) were scanned by a formal search of electronic databases (PubMed, EMBASE, Cochrane Library, Ovid, and clinical trials) from their inception to April 2018. A meta-analysis was conducted using Review Manager 5.3 to identify studies reporting the efficacy of MRAs use in post-MI patients with or without LVD.

RESULTS

Thirteen RCTs involving 11,365 individuals were eligible for this study. MRAs treatment reduced all-cause mortality by 16%, cardiovascular death by 16%, and death from heart failure (HF) by 22% in post-MI patients. MRAs use reduced all-cause mortality by 13% and cardiovascular death by 15% in post-MI patients with LVD, but there was no significant difference in all-cause mortality and cardiovascular death in post-MI patients without LVD (relative ratios [RR] 0.83, 95% confidence interval [CI] 0.26-2.69, P = .76, I = 0%; RR 1.01, 95% CI 0.33-3.09, P = .99, I = 0%). In 6 RCTs involving post-MI patients, MRAs treatment had a significant effect on improving left ventricular ejection fraction (LVEF) (mean difference 3.33, 95% CI 0.91-5.75, P = .007, I = 94%). Patients treated with MRAs did not show a decrease in recurrent MI or repeat revascularization compared with patients treated without MRAs (RR 0.95, 95% CI [0.80-1.12], P = .54, I = 0%; RR 1.09, 95% CI [0.79-1.50], P = .61, I = 0%). However, MRAs treatment significantly increased the incidence of hyperkalemia compared with patients treated without MRAs (RR 2.05, 95% CI [1.60, 2.61], P < .00001, I = 49%).

CONCLUSION

MRAs treatment reduced all-cause mortality, cardiovascular death, and death from HF in post-MI patients. MRAs treatment also demonstrated a significant improvement in LVEF. MRAs reduced cardiovascular death and all-cause mortality in patients with LVD. Eplerenone significantly reduced all-cause mortality and cardiovascular death in post-MI patients. However, MRAs failed to show any cardiovascular benefit in post-MI patients without LVD.

Clinical impact of mineralocorticoid receptor antagonists treatment after acute coronary syndrome in the real world: A propensity score matching analysis

BACKGROUND

Recent studies suggest that the benefit of mineralocorticoid receptor antagonists in the acute coronary syndrome setting is controversial. The aim of this study was to examine the current long-term prognostic benefit of mineralocorticoid receptor antagonists in patients with acute coronary syndrome.

MATERIAL AND METHODS

We conducted a retrospective cohort study of 8318 consecutive acute coronary syndrome patients. Baseline patient characteristics were examined and a follow-up period was established for registry of death, major cardiovascular adverse events and heart failure re-hospitalization. We performed a propensity-matching analysis to draw up two groups of patients paired according to whether or not they had been treated with mineralocorticoid receptor antagonists. The prognostic value of mineralocorticoid receptor antagonists to predict events during follow-up was analysed using Cox regression.

RESULTS

Among the study participants, only 524 patients (6.3%) were discharged on mineralocorticoid receptor antagonists. Patients on mineralocorticoid receptor antagonists had a different clinical and pharmacological profile. These differences disappeared after the propensity score analysis. The median follow-up was 40.7 months. After the propensity score analysis, the cardiovascular mortality and heart failure readmission rates were similar between patients who were discharged on mineralocorticoid receptor antagonists and those whose not. The use of mineralocorticoid receptor antagonists was only associated with a reduction in major cardiovascular adverse events (hazard ratio=0.83, 95% confidence interval 0.69-0.97, p=0.001).

CONCLUSIONS

Our results do not corroborate the long-term benefit of mineralocorticoid receptor antagonists to improve survival after acute coronary syndrome in a large cohort of patients with heart failure or reduced left ventricular ejection fraction and diabetes. Their prescription was associated with a significantly lower incidence of major cardiovascular adverse events during the long-term follow-up without effect on heart failure development.

Individual participant data analysis of two trials on aldosterone blockade in myocardial infarction

BACKGROUND

Two recent randomised trials studied the benefit of mineralocorticoid receptor antagonists (MRAs) in ST-segment elevation myocardial infarction (STEMI) irrespective or in absence of heart failure. The studies were both undersized to assess hard clinical endpoints. A pooled analysis was preplanned by the steering committees.

METHODS

We conducted a prespecified meta-analysis of patient-level data of patients with STEMI recruited in two multicentre superiority trials, randomised within 72 hours after symptom onset. Patients were allocated (1:1) to two MRA regimens: (1) an intravenous bolus of potassium canrenoate (200 mg) followed by oral spironolactone (25 mg once daily) versus standard therapy or (2) oral eplerenone (25-50 mg) versus placebo. The primary and key secondary outcomes, all-cause death and the composite of all-cause death or resuscitated sudden death, respectively, were assessed in the intention-to-treat population using a Cox model stratified on the study identifier.

RESULTS

Patients were randomly assigned to receive (n=1118) or not the MRA regimen (n=1123). After a median follow-up time of 188 days, the primary and secondary outcomes occurred in 5 (0.4%) and 17 (1.5%) patients (adjusted HR (adjHR) 0.31, 95% CI 0.11 to 0.86, p=0.03) and 6 (0.5%) and 22 (2%) patients (adjHR 0.26, 95% CI 0.10 to 0.65, p=0.004) in the MRA and control groups, respectively. There were also trends towards lower rates of cardiovascular death (p=0.06) and ventricular fibrillation (p=0.08) in the MRA group.

CONCLUSION

Our analysis suggests that compared with standard therapy, MRA regimens are associated with a reduction of death and death or resuscitated sudden death in STEMI.