STEMI and heart failure in the elderly: role of adverse remodeling

MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure

BACKGROUND

Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF).

PURPOSE

To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI.

STUDY TYPE

Prospective.

POPULATION

Multicenter registry of 759 reperfused STEMI patients (23.3% elderly).

FIELD STRENGTH/SEQUENCE

1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences.

ASSESSMENT

One-week MRI-derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI-derived LVEF as preserved (p-LVEF, ≥50%), mildly reduced (mr-LVEF, 41%-49%), or reduced (r-LVEF, ≤40%). Median follow-up was 5 [2.33-7.54] years.

STATISTICAL TESTS

Univariable (Student's t, Mann-Whitney U, chi-square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous-time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant.

RESULTS

Over the follow-up period, 79 (10.4%) patients presented AHF. MRI-LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91-0.98]) and elderly patients (HR 0.94 [0.91-0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p-LVEF) was noted in patients with r-LVEF both in nonelderly (HR 11.25 [5.67-22.32]) and elderly patients (HR 7.55 [3.29-17.34]). However, the mr-LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54-8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients.

DATA CONCLUSION

MRI-derived p-LVEF confers a favorable prognosis and r-LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr-LVEF category in the elderly group.

EVIDENCE LEVEL

2.

TECHNICAL EFFICACY

Stage 2.

Outcomes in diabetic patients treated with SGLT2-Inhibitors with acute myocardial infarction undergoing PCI: The SGLT2-I AMI PROTECT Registry

AIMS

To investigate in-hospital and long-term prognosis in T2DM patients presenting with acute myocardial infarction (AMI) treated with SGLT2-I versus other oral anti-diabetic agents (non-SGLT2-I users).

METHODS

In this multicenter international registry all consecutive diabetic AMI patients undergoing percutaneous coronary intervention between 2018 and 2021 were enrolled and, based on the admission anti-diabetic therapy, divided into SGLT-I users versus non-SGLT2-I users. The primary endpoint was defined as a composite of cardiovascular death, recurrent AMI, and hospitalization for HF (MACE). Secondary outcomes included i) in-hospital cardiovascular death, recurrent AMI, occurrence of arrhythmias, and contrast-induced acute kidney injury (CI-AKI); ii) long-term cardiovascular mortality, recurrent AMI, heart failure (HF) hospitalization.

RESULTS

The study population consisted of 646 AMI patients (with or without ST-segment elevation): 111 SGLT2-I users and 535 non-SGLT-I users. The use of SGLT2-I was associated with a significantly lower in-hospital cardiovascular death, arrhythmic burden, and occurrence of CI-AKI (all p < 0.05). During a median follow-up of 24 ± 13 months, the primary composite endpoint, as well as cardiovascular mortality and HF hospitalization were lower for SGLT2-I users compared to non-SGLT2-I patients (p < 0.04 for all). After adjusting for confounding factors, the use of SGLT2-I was identified as independent predictor of reduced MACE occurrence (HR=0.57; 95%CI:0.33-0.99; p = 0.039) and HF hospitalization (HR=0.46; 95%CI:0.21-0.98; p = 0.041).

CONCLUSIONS

In T2DM AMI patients, the use of SGLT2-I was associated with a lower risk of adverse cardiovascular outcomes during index hospitalization and long-term follow-up. Our findings provide new insights into the cardioprotective effects of SGLT2-I in the setting of AMI.

REGISTRATION

Data are part of the observational international registry: SGLT2-I AMI PROTECT.

CLINICALTRIALS

gov Identifier: NCT05261867.

Infarcted Myocardium-Primed Dendritic Cells Improve Remodeling and Cardiac Function After Myocardial Infarction by Modulating the Regulatory T Cell and Macrophage Polarization

BACKGROUND

Inflammatory responses play a critical role in left ventricular remodeling after myocardial infarction (MI). Tolerogenic dendritic cells (tDCs) can modulate immune responses, inducing regulatory T cells in a number of inflammatory diseases.

METHODS

We generated tDCs by treating bone marrow-derived dendritic cells with tumor necrosis factor-α and cardiac lysate from MI mice. We injected MI mice, induced by a ligation of the left anterior descending coronary artery in C57BL/6 mice, twice with tDCs within 24 hours and at 7 days after the ligation.

RESULTS

In vivo cardiac magnetic resonance imaging and ex vivo histology confirmed the beneficial effect on postinfarct left ventricular remodeling in MI mice treated with tDCs. Subcutaneously administered infarct lysate-primed tDCs near the inguinal lymph node migrated to the regional lymph node and induced infarct tissue-specific regulatory T-cell populations in the inguinal and mediastinal lymph nodes, spleen, and infarcted myocardium, indicating that a local injection of tDCs induces a systemic activation of MI-specific regulatory T cells. These events elicited an inflammatory-to-reparative macrophage shift. The altered immune environment in the infarcted heart resulted in a better wound remodeling, preserved left ventricular systolic function after myocardial tissue damage, and improved survival.

CONCLUSIONS

This study showed that tDC therapy in a preclinical model of MI was potentially translatable into an antiremodeling therapy for ischemic tissue repair.

Clinical profile, management, and mortality in very-elderly patients hospitalized with acute decompensated heart failure: An analysis from the ATTEND registry

BACKGROUND

Acute decompensated heart failure (ADHF) is a leading cause of hospitalization among the elderly. Discussion of optimal management of ADHF in older patients is a growing health care priority. The aim of this study was to examine the clinical profile, management, and mortality in patients admitted with ADHF according to age.

METHODS

We analyzed 4824 patients enrolled in the Acute Decompensated Heart Failure Syndromes registry from April 2007 to December 2011. Patient characteristics, management, and in-hospital outcomes were compared among four age groups (<65, 65-74, 75-84, and ≥85 years).

RESULTS

The mean age of the overall population was 73 years; approximately 20% were aged ≥85 years. Older patients were more likely to be women and have preserved left ventricular ejection fraction (LVEF) and decreased renal function. Intravenous treatments were well administered in both young and elderly patients irrespective of LVEF. Invasive procedures were less frequently performed in the eldest group. The median length of hospital stay was 21 days, and in-hospital cardiac death in the eldest group was four-fold higher than that in the youngest group (2.2% vs. 8.9%, P<0.001).

CONCLUSIONS

Clinical characteristics of ADHF differ considerably with age, and cardiac death increases linearly with age. Despite a higher rate of preserved systolic function in very-elderly individuals aged ≥85 years, in-hospital mortality was higher, suggesting that more suitable treatments for the elderly might be needed.

Global myocardial strain assessment by different imaging modalities to predict outcomes after ST-elevation myocardial infarction: A systematic review

AIM: To conduct a systematic review relating myocardial strain assessed by different imaging modalities for prognostication following ST-elevation myocardial infarction (STEMI).

METHODS: An online literature search was performed in PubMed and OVID^® electronic databases to identify any studies that assessed global myocardial strain parameters using speckle-tracking echocardiography (STE) and/or cardiac magnetic resonance imaging (CMR) techniques [either myocardial tagging or feature tracking (FT) software] in an acute STEMI cohort (days 0-14 post-event) to predict prognosis [either development of major adverse cardiac events (MACE)] or adverse left ventricular (LV) remodelling at follow-up (≥ 6 mo for MACE, ≥ 3 mo for remodelling). Search was restricted to studies within the last 20 years. All studies that matched the pre-defined search criteria were reviewed and their results interpreted. Due to considerable heterogeneity between studies, meta-analysis was not performed.

RESULTS: A total of seven studies (n = 7) were identified that matched the search criteria. All studies used STE to evaluate strain parameters - five (n = 5) assessed global longitudinal strain (GLS) (n = 5), one assessed GLS rate (GLS-R) (n = 1) and one assessed both (n = 1). Three studies showed that GLS independently predicted the development of adverse LV remodelling by multivariate analysis - odds ratio between 1.19 (CI: 1.04-1.37, P < 0.05) and 10 (CI: 6.7-14, P < 0.001) depending on the study. Four studies showed that GLS predicted the development of MACE - hazard ratio (HR) between 1.1 (CI: 1-1.1, P = 0.006) and 2.34 (1.10-4.97, P < 0.05). One paper found that GLS-R could significantly predict MACE - HR 18 (10-35, P < 0.001) - whilst another showed it did not. GLS < -10.85% had sensitivity/specificity of 89.7%/91% respectively for predicting the development of remodelling whilst GLS < -13% could predict the development of MACE with sensitivity/specificity of 100%/89% respectively. No suitable studies were identified that assessed global strain by CMR tagging or FT techniques.

CONCLUSION: GLS measured acutely post-STEMI by STE is a predictor of poor prognosis. Further research is needed to show that this is true for CMR-based techniques.

Risk assessment of post-infarction heart failure. Systematic review on the role of emerging biomarkers

The prognostic significance of cardiospecific troponins and natriuretic peptides in patients with myocardial ischemia is well established, and their measurement is now endorsed by the most important guidelines and recommendations for diagnosis and management of heart failure (HF). Additional biomarkers have also been investigated to support clinical judgment and diagnostic imaging in the stratification of risk of cardiac dysfunction in patients with myocardial infarction (MI). We have performed a systematic analysis of the current scientific literature regarding the most important biomarkers of HF, selecting all prospective studies with adequate sample size (i.e. >100 patients) that have assessed, during the early phase of myocardial ischemia, the prognostic value of emergent biomarkers for new-onset HF or deterioration of cardiac function in patients with MI. This analysis has provided some good evidence suggesting that, in most cases, the use of diagnostic biomarkers of cardiac dysfunction does not translate into efficient risk prediction of HF. However, some notable exceptions were found, including biomarkers of cardiac fibrosis (especially galectin-3), growth differentiation factor-15 (GDF-15), osteoprotegerin, C-reactive protein (CRP), and red blood cell distribution width (RDW). Nevertheless, future studies with well-defined characteristics including the use of larger sample sizes, standardized end points, and replication populations, along with benchmark analyses against other consolidated biomarkers (i.e. cardiospecific troponins and natriuretic peptides), should be planned. Such evaluations will help to establish whether an integrated approach including biomarkers of different pathogenetic pathways - for example, apoptosis, stress of cardiomyocytes, cardiac fibrosis, inflammation, and extra-cardiac involvement - may be cost effective for identifying patients at increased risk of developing HF, and who, therefore, may benefit from a tailored therapeutic strategy.

AICAR-dependent AMPK activation improves scar formation in the aged heart in a murine model of reperfused myocardial infarction

We have demonstrated that scar formation after myocardial infarction (MI) is associated with an endogenous pool of CD44(pos)CD45(neg) multipotential mesenchymal stem cells (MSC). MSC differentiate into fibroblasts secreting collagen that forms a scar and mature into myofibroblasts that express alpha smooth muscle actin (α-SMA) that stabilizes the scar. In the aging mouse, cardiac repair after MI is associated with impaired differentiation of MSC; MSC derived from the aged hearts form dysfunctional fibroblasts that deposit less collagen in response to transforming growth factor beta-1 (TGF-β1) and poorly mature into myofibroblasts. We found in vitro that the defect in myofibroblast maturation can be remedied by AICAR, which activates non-canonical TGF-β signaling through AMP-activated protein kinase (AMPK). In the present study, we injected aged mice with AICAR and subjected them to 1h occlusion of the left anterior descending artery (LAD) and then reperfusion for up to 30days. AICAR-dependent AMPK signaling led to mobilization of an endogenous CD44(pos)CD45(neg) MSC and its differentiation towards fibroblasts and myofibroblasts in the infarct. This was accompanied by enhanced collagen deposition and collagen fiber maturation in the scar. The AICAR-treated group has demonstrated reduced adverse remodeling as indicated by improved apical end diastolic dimension but no changes in ejection fraction and cardiac output were observed. We concluded that these data indicate the novel, previously not described role of AMPK in the post-MI scar formation. These findings can potentially lead to a new therapeutic strategy for prevention of adverse remodeling in the aging heart.

Atrial fibrillation and heart failure in the elderly

Atrial fibrillation (AF) is a common clinical problem in elderly patients and especially in those with heart failure (HF). It is a major risk factor for serious cardiovascular events, such as stroke, HF and premature death. Both the prevalence and incidence of AF increase with age and its prevalence in the United States are estimated at more than 2.2 million, with nearly 75% of patients aged >65 years. Aging-related atrial remodeling with fibrosis, dilation and mitochondrial DNA mutations predispose elderly patients to AF. Current management options for AF, including rate control and anticoagulation therapy, can be successfully applied to the elderly population. New antiarrhythmic and anticoagulation medications such as dronedarone and dabigatran, respectively, can impact the approach to therapy in the elderly. Non-pharmacological options such as catheter-based ablation have also gained prominence and have been incorporated into the guidelines for management of AF. However, more trials in the elderly and very elderly segments are needed to clarify the safety and long-term efficacy of the new treatment options.

Heart failure in elderly patients: distinctive features and unresolved issues

The prevalence of heart failure (HF) increases with age. While clinical trials suggest that contemporary evidence-based HF therapies have reduced morbidity and mortality, these trials largely excluded the elderly. Questions remain regarding the clinical characteristics of elderly HF patients and the impact of contemporary therapies on their outcomes. This review presents the epidemiology of HF in the elderly and summarizes the data on the pathophysiology of the ageing heart. The clinical characteristics, treatment patterns, and outcomes of elderly HF patients are explored. Finally, the main gaps regarding HF therapies in the elderly and the opportunities for future trials are highlighted.

Clinical effectiveness of telmisartan alone or in combination therapy for controlling blood pressure and vascular risk in the elderly

Elderly patients (age ≥ 65 years) with hypertension are at high risk for vascular complications, especially when diabetes is present. Antihypertensive drugs that inhibit the renin-angiotensin system have been shown to be effective for controlling blood pressure in adult and elderly patients. Importantly, renin-angiotensin system inhibitors were shown to have benefits beyond their classic cardioprotective and vasculoprotective effects, including reducing the risk of new-onset diabetes and associated cardiovascular effects. The discovery that the renin-angiotensin system inhibitor and angiotensin II type 1 (AT(1)) receptor blocker (ARB), telmisartan, can selectively activate the peroxisome proliferator-activated receptor-γ (PPARγ, an established antidiabetic drug target) provides the unique opportunity to prevent and treat cardiovascular complications in high-risk elderly patients with hypertension and new-onset diabetes. Two large clinical trials, ONTARGET (Ongoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomized AssessmeNt Study in ACE-I iNtolerant subjects with cardiovascular disease) have assessed the cardioprotective and antidiabetic effects of telmisartan. The collective data suggest that telmisartan is a promising drug for controlling hypertension and reducing vascular risk in high-risk elderly patients with new-onset diabetes.