Myocardial infarction outcomes: "the times, they are a-changin..."

Impact of inflammation-mediated response on pan-coronary plaque vulnerability, myocardial viability and ventricular remodeling in the postinfarction period - the VIABILITY study: Protocol for a non-randomized prospective clinical study

INTRODUCTION

While the role of inflammation in acute coronary events is well established, the impact of inflammatory-mediated vulnerability of coronary plaques from the entire coronary tree, on the extension of ventricular remodeling and scaring, has not been clarified yet.

MATERIALS AND METHODS

The present manuscript describes the procedures of the VIABILITY trial, a descriptive prospective single-center cohort study. The main purpose of this trial is to assess the link between systemic inflammation, pan-coronary plaque vulnerability (referring to the plaque vulnerability within the entire coronary tree), myocardial viability and ventricular remodeling in patients who had suffered a recent ST-segment elevation acute myocardial infarction (STEMI). One hundred patients with STEMI who underwent successful revascularization of the culprit lesion in the first 12 hours after the onset of symptoms will be enrolled in the study. The level of systemic inflammation will be evaluated based on the serum biomarker levels (hs-CRP, matrix metalloproteinases, interleukin-6) in the acute phase of the myocardial infarction (MI) and at 1 month. Pan-coronary plaque vulnerability will be assessed based on serum biomarkers known to be associated with increased plaque vulnerability (V-CAM or I-CAM) and at 1 month after infarction, based on computed tomographic angiography analysis of vulnerability features of all coronary plaques. Myocardial viability and remodeling will be assessed based on 3D speckle tracking echocardiography associated with dobutamine infusion and LGE-CMR associated with post-processing imaging methods. The study population will be categorized in 2 subgroups: subgroup 1 - subjects with STEMI and increased inflammatory response at 7 days after the acute event (hs-CRP ≥ 3 mg/dl), and subgroup 2 - subjects with STEMI and no increased inflammatory response at 7 days (hs-CRP < 3 mg/dl). Study outcomes will consist in the rate of post-infarction heart failure development and the major adverse events (MACE) rate.

CONCLUSION

VIABILITY is the first prospective study designed to evaluate the influence of infarct-related inflammatory response on several major determinants of post-infarction outcomes, such as coronary plaque vulnerability, myocardial viability, and ventricular remodeling.

Selective inhibition of receptor activator of NF-κB ligand (RANKL) in hematopoietic cells improves outcome after experimental myocardial infarction

The RANK (receptor activator of nuclear factor κB)/RANKL (RANK ligand)/OPG (osteoprotegerin) axis is activated after myocardial infarction (MI), but its pathophysiological role is not well understood. Here, we investigated how global and cell compartment-selective inhibition of RANKL affects cardiac function and remodeling after MI in mice. Global RANKL inhibition was achieved by treatment of human RANKL knock-in (huRANKL-KI) mice with the monoclonal antibody AMG161. huRANKL-KI mice express a chimeric RANKL protein wherein part of the RANKL molecule is humanized. AMG161 inhibits human and chimeric but not murine RANKL. To dissect the pathophysiological role of RANKL derived from hematopoietic and mesenchymal cells, we selectively exchanged the hematopoietic cell compartment by lethal irradiation and across-genotype bone marrow transplantation between wild-type and huRANKL-KI mice, exploiting the specificity of AMG161. After permanent coronary artery ligation, mice were injected with AMG161 or an isotype control antibody over 4 weeks post-MI. MI increased RANKL expression mainly in cardiomyocytes and scar-infiltrating cells 4 weeks after MI. Only inhibition of RANKL derived from hematopoietic cellular sources, but not global or mesenchymal RANKL inhibition, improved post-infarct survival and cardiac function. Mechanistically, hematopoietic RANKL inhibition reduced expression of the pro-inflammatory cytokine IL-1ß in the cardiac cellular infiltrate. In conclusion, inhibition of RANKL derived from hematopoietic cellular sources is beneficial to maintain post-ischemic cardiac function by reduction of pro-inflammatory cytokine production. KEY MESSAGES: Experimental myocardial infarction (MI) augments cardiac RANKL expression in mice. RANKL expression is increased in cardiomyocytes and scar-infiltrating cells after MI. Global or mesenchymal cell RANKL inhibition has no influence on cardiac function after MI. Inhibition of RANKL derived from hematopoietic cells improves heart function post-MI. Hematopoietic RANKL inhibition reduces pro-inflammatory cytokines in scar-infiltrating cells.

Trends in 28-day and 1-year mortality rates in patients hospitalized for a first acute myocardial infarction in Norway during 2001-2009: a "Cardiovascular disease in Norway" (CVDNOR) project

OBJECTIVE

The aim of this study was to investigate the trends in 28-day and 1-year mortality rates in patients hospitalized for a first acute myocardial infarction (AMI) in Norway during the period 2001-2009. Potential age group and gender differences in these trends were also examined.

DESIGN, SUBJECTS AND SETTING

In this retrospective nationwide cohort study, patients hospitalized for a first AMI between 2001 and 2009 were identified in the Cardiovascular Disease in Norway 1994-2009 (CVDNOR) project and followed for 1 year.

MAIN OUTCOME MEASURES

Trends in 28-day and 1-year mortality [both all-cause and cardiovascular disease (CVD) mortality] were investigated.

RESULTS

A total of 115,608 patients (60.6% men) were hospitalized for a first AMI during the study period. Mortality at 28 days was reduced annually by 3.8% overall and by 6.7%, 4.1% and 2.6% in patients aged 25-64, 65-84 and ≥85 years, respectively (all Ptrend < 0.001). In addition, 1-year all-cause mortality was reduced annually by 2.0% overall (Ptrend < 0.001) and by 3.7% (Ptrend = 0.02), 2.5% (Ptrend < 0.001) and 1.1% (Ptrend < 0.001) in patients aged 25-64, 65-84 and ≥85 years, respectively. Furthermore, 1-year CVD mortality was reduced overall by 6.2% annually; a reduction was observed in all age groups. Finally, 1-year non-CVD mortality increased annually overall by 3.9% due to an increase in patients aged ≥65 years.

CONCLUSION

Mortaity at 28 days after the first AMI declinedin Norway between 2001 and 2009 in both men and women and in all age groups. All-cause mortality at 1 year also declined both in men and women due to decreases in CVD mortality rates, whilst non-CVD mortality rates increased amongst patients ≥65 years of age.

Contemporary trends in heart failure with reduced and preserved ejection fraction after myocardial infarction: a community study

Major changes have recently occurred in the epidemiology of myocardial infarction (MI) that could possibly affect outcomes such as heart failure (HF). Data describing trends in HF after MI are scarce and conflicting and do not distinguish between preserved and reduced ejection fraction (EF). We evaluated temporal trends in HF after MI. All residents of Olmsted County, Minnesota (n = 2,596) who had a first-ever MI diagnosed in 1990-2010 and no prior HF were followed-up through 2012. Framingham Heart Study criteria were used to define HF, which was further classified according to EF. Both early-onset (0-7 days after MI) and late-onset (8 days to 5 years after MI) HF were examined. Changes in patient presentation were noted, including fewer ST-segment-elevation MIs, lower Killip class, and more comorbid conditions. Over the 5-year follow-up period, 715 patients developed HF, 475 of whom developed it during the first week. The age- and sex-adjusted risk declined from 1990-1996 to 2004-2010, with hazard ratios of 0.67 (95% confidence interval (CI): 0.54, 0.85) for early-onset HF and 0.63 (95% CI: 0.45, 0.86) for late-onset HF. Further adjustment for patient and MI characteristics yielded hazard ratios of 0.86 (95% CI: 0.66, 1.11) and 0.63 (95% CI: 0.45, 0.88) for early- and late-onset HF, respectively. Declines in early-onset and late-onset HF were observed for HF with reduced EF (<50%) but not for HF with preserved EF, indicating a change in the case mix of HF after MI that requires new prevention strategies.