Congestive heart failure with preserved left ventricular systolic function after acute myocardial infarction: clinical and prognostic implications

Trajectories and determinants of left ventricular ejection fraction after the first myocardial infarction in the current era of primary coronary interventions

BACKGROUND

Left ventricular ejection fraction (EF) is an independent predictor of adverse outcomes after myocardial infarction (MI). However, current data on trajectories and determinants of EF are scarce. The present study aimed to describe the epidemiology of EF after MI.

METHODS

Data from a single-center prospectively-designed registry of consecutive patients hospitalized at a large tertiary cardiology center were utilized.

RESULTS

Out of 1,593 patients in the registry, 1,065 were hospitalized for MI type I (65.4% STEMI) and had no previous history of heart failure or MI. At discharge, EF < 40% was present in 238 (22.3%), EF 40-50% in 326 (30.6%) and EF > 50% in 501 (47.0%). Patients with EF < 40% were often those who suffered subacute and anterior STEMI, had higher heart rate at admission and higher maximal troponin level, and had more often HF signs requiring intravenous diuretics. Among subjects with EF < 40%, the follow-up EF was available in 166 (80% of eligible). Systolic function recovered to EF > 50% in 39 (23.1%), slightly improved to EF 40-50% in 44 (26.0%) and remained below 40% in 86 (50.9%). Systolic function improvement to EF > 40% was predicted by lower severity of coronary atherosclerosis, lower leukocyte count, and the absence of atrial fibrillation.

CONCLUSIONS

Despite recent improvements in in-hospital MI care, one in five patients has systolic dysfunction at hospital discharge. Out of these, EF improves in 51%, and full recovery is observed in 23%. The severity of coronary atherosclerosis, inflammatory response to MI, and atrial fibrillation may affect EF recovery.

Acute Decompensated Heart Failure in the Setting of Acute Coronary Syndrome

Acute coronary syndrome (ACS) is frequently complicated by evidence of heart failure (HF). Those at highest risk for acute decompensated HF in the setting of ACS (ACS-HF) are older, female, and have preexisting heart disease, type 2 diabetes mellitus, hypertension, and/or kidney disease. The presence of ACS-HF is strongly associated with higher mortality and more frequent readmissions, especially for HF. Low implementation of guideline-directed medical therapy has further complicated the clinical care of this high-risk population. Improved utilization of current therapies, coupled with further investigation of strategies to manage ACS-HF, is desperately needed to improve outcomes in this vulnerable population, and the results of currently ongoing or recently concluded ACS-HF studies in this population are of great interest. In this review, we explore the pathophysiology, epidemiology, risk factors, and outcomes for patients with ACS-HF, and describe both existing evidence for management of this challenging condition and areas requiring further research.

Assessment of Selected Baseline and Post-PCI Electrocardiographic Parameters as Predictors of Left Ventricular Systolic Dysfunction after a First ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To assess the performance of ten electrocardiographic (ECG) parameters regarding the prediction of left ventricular systolic dysfunction (LVSD) after a first ST-segment-elevation myocardial infarction (STEMI).

METHODS

We analyzed 249 patients (74.7% males) treated with primary percutaneous coronary intervention (PCI) included into a single-center cohort study. We sought associations between baseline and post-PCI ECG parameters and the presence of LVSD (defined as left ventricular ejection fraction [LVEF] ≤ 40% on echocardiography) 6 months after STEMI.

RESULTS

Patients presenting with LVSD (n = 52) had significantly higher values of heart rate, number of leads with ST-segment elevation and pathological Q-waves, as well as total and maximal ST-segment elevation at baseline and directly after PCI compared with patients without LVSD. They also showed a significantly higher prevalence of anterior STEMI and considerably wider QRS complex after PCI, while QRS duration measurement at baseline showed no significant difference. Additionally, patients presenting with LVSD after 6 months showed markedly more severe ischemia on admission, as assessed with the Sclarovsky-Birnbaum ischemia score, smaller reciprocal ST-segment depression at baseline and less profound ST-segment resolution post PCI. In multivariate regression analysis adjusted for demographic, clinical, biochemical and angiographic variables, anterior location of STEMI (OR 17.78; 95% CI 6.45-48.96; p < 0.001), post-PCI QRS duration (OR 1.56; 95% CI 1.22-2.00; p < 0.001) expressed per increments of 10 ms and impaired post-PCI flow in the infarct-related artery (IRA; TIMI 3 vs. <3; OR 0.14; 95% CI 0.04-0.46; p = 0.001) were identified as independent predictors of LVSD (Nagelkerke's pseudo R2 for the logistic regression model = 0.462). Similarly, in multiple regression analysis, anterior location of STEMI, wider post-PCI QRS, higher baseline number of pathological Q-waves and a higher baseline Sclarovsky-Birnbaum ischemia score, together with impaired post-PCI flow in the IRA, higher values of body mass index and glucose concentration on admission were independently associated with lower values of LVEF at 6 months (corrected R2 = 0.448; p < 0.00001).

CONCLUSIONS

According to our study, baseline and post-PCI ECG parameters are of modest value for the prediction of LVSD occurrence 6 months after a first STEMI.

Clinical and prognostic correlates of pulmonary congestion in coronary computed tomography angiography data sets

BACKGROUND

Signs of pulmonary congestion obtained from cardiac computed tomography angiographic (coronary CTA) images have not previously been related to clinical congestion or outcome and the clinical value is, therefore, unknown. Our objective was to test the hypothesis that signs of pulmonary congestion predict clinical heart failure and adverse outcome in patients with myocardial infarction.

METHODS

Coronary CTA was performed before invasive treatment in 400 prospectively included patients with non ST segment elevation myocardial infarction in an observational study. Using a previously described chest computed tomography evaluation algorithm, patients were classified as having "no congestion", "mild to moderate congestion" or "severe congestion".

RESULTS

Using multivariate analyses, presence of pulmonary congestion on coronary CTA images was associated with age, female gender, left ventricular ejection fraction (LVEF) and left atrial size. The diagnostic accuracy for predicting clinical heart failure, defined as Killip class >1, was: sensitivity: 83%, specificity: 69%, positive predictive value: 25%, and negative predictive value: 97%. The median follow-up time was 50 months and the study end-point of death or hospitalization due to heart failure was reached in 68 (16%) patients. In a Cox proportional hazards model with adjustments for known risk factors and Killip class, the presence of "mild to moderate congestion" and "severe congestion" was independently associated with adverse outcome (Hazard ratio: 2.6 (95% CI:1.3-5.0) and 3.2 (1.3-7.5)).

CONCLUSION

Signs of pulmonary congestion on coronary CTA images are closely correlated to cardiac dysfunction, predict clinical heart failure, and provide prognostic value independent of LVEF and Killip class.

Different prognostic factors according to left ventricular systolic function in patients with acute myocardial infarction

BACKGROUND

Initial left ventricular (LV) systolic function is a main determinant of clinical outcomes in patients with acute myocardial infarction (AMI). This study was performed to investigate whether AMI patients have different prognostic factors according to their baseline LV systolic function.

METHODS

A total of 12,988 patients with AMI from a nationwide database were analyzed. Major adverse cardiovascular events (MACEs) within 12months of AMI, including death, nonfatal myocardial infarction (MI), and revascularization, were assessed.

RESULTS

Patients were stratified into two groups according to LV ejection fraction (LVEF): those with LVEF<40% and those with LVEF≥40%. Patients with LVEF<40% (n=1962, 15.1%) were older and had more unfavorable cardiovascular risk factors than those with LVEF≥40% (n=11,026, 84.9%). The rate of MACE was higher in patients with LVEF<40% than in those with LVEF≥40% (26.8% vs 11.4%, p<0.001). Independent predictors of 12-month MACEs in patients with LVEF≥40% were history of MI, high Killip stage, three-vessel disease, and lower renal function, which are already known as risk factors. However, diabetes mellitus (hazard ratio [HR], 1.68; 95% confidence interval [CI], 1.17-2.40; p=0.008), and the use of rennin-angiotensin system (RAS) blockers (HR, 0.63; 95% CI, 0.41-0.95; p=0.029) were independent factors for 12-month MACE in patients with LVEF <40%.

CONCLUSIONS

Prognostic factors determining 12-month MACE after AMI are different according to LVEF. Management following AMI should be tailored according to their LV systolic function.

Management and Long-Term Outcome of Acute Coronary Syndrome Patients Presenting with Heart Failure in a Contemporary New Zealand Cohort (ANZACS-QI 4)

BACKGROUND

Acute heart failure (HF) associated with an acute coronary syndrome (ACS) predicts adverse outcome. There have been important recent improvements in ACS management. Our aim was to describe the management and outcomes in those with and without HF in a contemporary ACS cohort.

METHODS

Consecutive patients presenting with ACS between 2007 and 2011 were enrolled in the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry. Outcomes and medication dispensing were obtained using anonymised linkage to national data sets. A summary pharmacotherapy measure of "quadruple therapy" was defined as dispensing of at least one agent from each of the four evidence-based classes - anti-platelet, statin, angiotensin converting enzyme inhibitor/angiotensin receptor blocker and beta blocker.

RESULTS

Of 3743 ACS patients 14% had acute HF. Acute heart failure patients were older (69.2±12.6 vs 62.3±12.8 years, p<0.001), less likely to have coronary angiography (66% vs 86%, p<0.001) and revascularisation (46% vs 62%, p<0.001). Immediate post-discharge quadruple therapy was higher for those with than without HF (61% vs 55%, p=0.02) but fell to similar levels by one-year (45% vs 53%, p=0.55). At four years follow-up nearly half of those presenting with ACS and HF had died. After adjustment, HF remained a strong predictor of death within 28 days (OR 2.9, 95%CI 1.5 - 5.5) and beyond 28 days (HR 1.8, 95%CI 1.5 - 2.3).

CONCLUSION

Acute heart failure complicating ACS is associated with heightened risk of short-term and long-term mortality. One in three ACS patients with HF did not have coronary angiography and less than half received quadruple therapy a year after presentation.

Mortality Associated With Heart Failure After Myocardial Infarction: A Contemporary Community Perspective

BACKGROUND

Contemporary data are lacking on the prognostic importance of heart failure (HF) after myocardial infarction (MI). We evaluated the prognostic impact of HF post MI according to preserved/reduced ejection fraction and the timing of its occurrence.

METHODS AND RESULTS

All Olmsted County, Minnesota, residents (n=2596) with incident MI diagnosed in 1990 to 2010 and no prior HF were followed through March 2013. Cox models were used to examine (1) the hazard ratios for death associated with HF type and timing and (2) secular trends in survival by HF status. During a mean follow-up of 7.6 years, there were 1116 deaths, 634 in the 902 patients who developed HF (70%) and 482 in the 1694 patients who did not develop HF (28%). After adjustment for age and sex, HF as a time-dependent variable was strongly associated with mortality (hazard ratio =3.31, 95% confidence interval: 2.93-3.75), particularly from cardiovascular causes (hazard ratio =4.20, 95% confidence interval: 3.50-5.03). Further adjustment for MI severity and comorbidity, acute treatment, and recurrent MI moderately attenuated these associations (hazard ratio =2.49 and 2.94 for all-cause and cardiovascular mortality, respectively). Mortality did not differ by ejection fraction, but was higher for delayed- versus early-onset HF (P for heterogeneity =0.002). The age- and sex-adjusted 5-year survival estimates in 2001 to 2010 versus 1990 to 2000 were 82% and 81% among HF-free and 61% and 54% among HF patients, respectively (P for heterogeneity of trends =0.05).

CONCLUSIONS

HF markedly increases the risk of death after MI. This excess risk is similar regardless of ejection fraction but greater for delayed- versus early-onset HF. Mortality after MI declined over time, primarily as a result of improved HF survival.

The direct incorporation of perfusion defect information to define ischemia and infarction in a finite element model of the left ventricle

This paper describes the process in which complex lesion geometries (specified by computer generated perfusion defects) are incorporated in the description of nonlinear finite element (FE) mechanical models used for specifying the motion of the left ventricle (LV) in the 4D extended cardiac torso (XCAT) phantom to simulate gated cardiac image data. An image interrogation process was developed to define the elements in the LV mesh as ischemic or infarcted based upon the values of sampled intensity levels of the perfusion maps. The intensity values were determined for each of the interior integration points of every element of the FE mesh. The average element intensity levels were then determined. The elements with average intensity values below a user-controlled threshold were defined as ischemic or infarcted depending upon the model being defined. For the infarction model cases, the thresholding and interrogation process were repeated in order to define a border zone (BZ) surrounding the infarction. This methodology was evaluated using perfusion maps created by the perfusion cardiac-torso (PCAT) phantom an extension of the 4D XCAT phantom. The PCAT was used to create 3D perfusion maps representing 90% occlusions at four locations (left anterior descending (LAD) segments 6 and 9, left circumflex (LCX) segment 11, right coronary artery (RCA) segment 1) in the coronary tree. The volumes and shapes of the defects defined in the FE mechanical models were compared with perfusion maps produced by the PCAT. The models were incorporated into the XCAT phantom. The ischemia models had reduced stroke volume (SV) by 18-59 ml. and ejection fraction (EF) values by 14-50% points compared to the normal models. The infarction models, had less reductions in SV and EF, 17-54 ml. and 14-45% points, respectively. The volumes of the ischemic/infarcted regions of the models were nearly identical to those volumes obtained from the perfusion images and were highly correlated (R² = 0.99).

Intravenous immunoglobulin does not reduce left ventricular remodeling in patients with myocardial dysfunction during hospitalization after acute myocardial infarction

BACKGROUND

Left ventricular (LV) remodeling takes place after acute myocardial infarction (MI), potentially leading to overt heart failure (HF). Enhanced inflammation may contribute to LV remodeling. Our hypothesis was that the immunomodulating effects of intravenous immunoglobulin (IVIg) would be beneficial in patients with impaired myocardial function after MI by reducing myocardial remodeling and improving myocardial function.

METHODS

Sixty-two patients with acute MI treated by percutaneous coronary intervention, with depressed LV ejection fraction (LVEF) were randomized in a double-blinded fashion to IVIg as induction therapy and thereafter as monthly infusions or placebo for 26 weeks. The primary end point was changes in LVEF from baseline to 6 months as assessed by MRI.

RESULTS

Our main findings were: (i) LVEF increased significantly from 38 ± 10 (mean ± SD) to 45 ± 13% after IVIg and from 42 ± 9 to 49 ± 12% after placebo with no difference between the groups. (ii) The scar area decreased significantly by 3% and 5% in the IVIg and placebo group, respectively, with no difference between the groups. (iii) During the induction therapy (baseline to day 5), IVIg induced both inflammatory (e.g., increase in tumor necrosis factor α and monocyte chemoattractant protein-1) and anti-inflammatory (e.g., increase in interleukin-10 and decrease in leukocyte counts) variables, but during maintenance therapy there were no differences in changes of inflammatory mediators between IVIg and placebo.

CONCLUSIONS

IVIg therapy after ST elevation MI managed by primary PCI does not affect LV remodeling or function. This illustrates the challenges of therapeutic intervention directed against the cytokine network, to prevent post-MI remodeling.

Usefulness of C-reactive protein as a marker of early post-infarct left ventricular systolic dysfunction

Objective

To assess the usefulness of in-hospital measurement of C-reactive protein (CRP) concentration in comparison to well-established risk factors as a marker of post-infarct left ventricular systolic dysfunction (LVSD) at discharge.

Materials and methods

Two hundred and four consecutive patients with ST-segment-elevation myocardial infarction (STEMI) were prospectively enrolled into the study. CRP plasma concentrations were measured before reperfusion, 24 h after admission and at discharge with an ultra-sensitive latex immunoassay.

Results

CRP concentration increased significantly during the first 24 h of hospitalization (2.4 ± 1.9 vs. 15.7 ± 17.0 mg/L; p < 0.001) and persisted elevated at discharge (14.7 ± 14.7 mg/L), mainly in 57 patients with LVSD (2.4 ± 1.8 vs. 25.0 ± 23.4 mg/L; p < 0.001; CRP at discharge 21.9 ± 18.6 mg/L). The prevalence of LVSD was significantly increased across increasing tertiles of CRP concentration both at 24 h after admission (13.2 vs. 19.1 vs. 51.5 %; p < 0.0001) and at discharge (14.7 vs. 23.5 vs. 45.6 %; p < 0.0001). Multivariate analysis demonstrated CRP concentration at discharge to be an independent marker of early LVSD (odds ratio of 1.38 for a 10 mg/L increase, 95 % confidence interval 1.01–1.87; p < 0.04).

Conclusion

Measurement of CRP plasma concentration at discharge may be useful as a marker of early LVSD in patients after a first STEMI.

Changes in left ventricular filling patterns after repeated injection of autologous bone marrow cells in heart failure patients

OBJECTIVES

We have previously shown that repeated intracoronary infusion of bone marrow cells (BMSC) did not improve left ventricular (LV) ejection fraction in patients with chronic ischemic heart failure. However, the impact of BMSC therapy on LV diastolic filling has remained uncertain.

DESIGN

Thirty two patients with LV ejection fraction less than 40% were studied. Each patient underwent three baseline echocardiograms to ensure stable LV filling. Infusion of BMSC was given at baseline and again after four months. Echocardiograms were repeated four, eight and 12 months after the first intervention. Main outcome measures were the ratio of transmitral flow (E) velocity to early mitral annulus (e') velocity (E/e'), left atrial (LA) volume and plasma levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP).

RESULTS

During the initial observational period there were no changes in main outcome. After treatment with intracoronary BMSC a significant decrease was observed in E/e' ratio (14.7+/-6.7 vs. 13.2+/-7.7, p=0.04), LA volume (90+/-25 ml vs. 80+/-26 ml, p=0.006) and plasma NT-pro-BNP (p=0.03). The effect was greatest in patients who received the largest amount of CD34(+) cells.

CONCLUSION

In this non-randomised study repeated intracoronary BMSC infusions had a beneficial effect on LV filling in patients with chronic ischemic heart failure. Randomised studies are warranted.

Ventricular-arterial uncoupling in heart failure with preserved ejection fraction after myocardial infarction in dogs - invasive versus echocardiographic evaluation

Background

Heart failure with preserved left ventricular ejection fraction and abnormal diastolic function is commonly observed after recovery from an acute myocardial infarction. The aim of this study was to investigate the physiopathology of heart failure with preserved ejection fraction in a model of healed myocardial infarction in dogs.

Methods

Echocardiography, levels of neurohormones and conductance catheter measurements of left ventricular pressure-volume relationships were obtained in 17 beagle dogs 2 months after a coronary artery ligation, and in 6 controls.

Results

Healed myocardial infarction was associated with preserved echocardiographic left ventricular ejection fraction (0.57 ± 0.01, mean ± SEM) and altered Doppler mitral indices of diastolic function. NT-proBNP was increased, aldosterone was decreased, and norepinephrine was unchanged. Invasive measurements showed a markedly decreased end-systolic elastance (2.1 ± 0.2 vs 6.1 ± 0.8, mmHg/ml, p < 0.001) and end-systolic elastance to effective arterial elastance ratio (0.6 ± 0.1 vs 1.4 ± 0.2, p < 0.001), with altered active relaxation (dP/dtmin -1992 ± 71 vs -2821 ± 305, mmHg/s, p < 0.01) but preserved left ventricular capacitance (70 ± 6 vs 61 ± 3, ml at 20 mmHg, p = NS) and stiffness constant. Among echocardiographic variables, the wall motion score index was the most reliable indicator of cardiac contractility while E', E/A and E'/A' were correlated to dP/dtmin.

Conclusions

In the canine model of healed myocardial infarction induced by coronary ligation, heart failure is essentially characterized by an altered contractility with left ventricular-arterial uncoupling despite vascular compensation rather than by abnormal diastolic function

Renal impairment and heart failure with preserved ejection fraction early post-myocardial infarction

AIM

To study if impaired renal function is associated with increased risk of peri-infarct heart failure (HF) in patients with preserved ejection fraction (EF).

METHODS

Patients with occluded infarct-related arteries (IRAs) between 1 to 28 d after myocardial infarction (MI) were grouped into chronic kidney disease (CKD) stages based on estimated glomerular filtration rate (eGFR). Rates of early post-MI HF were compared among eGFR groups. Logistic regression was used to explore independent predictors of HF.

RESULTS

Reduced eGFR was present in 71.1% of 2160 patients, with significant renal impairment (eGFR < 60 mL/min every 1.73 m(2)) in 14.8%. The prevalence of HF was higher with worsening renal function: 15.5%, 17.8% and 29.4% in patients with CKD stages 1, 2 and 3 or 4, respectively (P < 0.0001), despite a small absolute difference in mean EF across eGFR groups: 48.2 ± 10.0, 47.9 ± 11.3 and 46.2 ± 12.1, respectively (P = 0.02). The prevalence of HF was again higher with worsening renal function among patients with preserved EF: 10.1%, 13.6% and 23.6% (P < 0.0001), but this relationship was not significant among patients with depressed EF: 27.1%, 26.2% and 37.9% (P = 0.071). Moreover, eGFR was an independent correlate of HF in patients with preserved EF (P = 0.003) but not in patients with depressed EF (P = 0.181).

CONCLUSION

A significant proportion of post-MI patients with occluded IRAs have impaired renal function. Impaired renal function was associated with an increased rate of early post-MI HF, the association being strongest in patients with preserved EF. These findings have implications for management of peri-infarct HF.

Depressive symptoms increase risk of rehospitalisation in heart failure patients with preserved systolic function

AIMS

To examine the impact of depressive symptoms on rehospitalisation for heart failure exacerbation in patients with preserved systolic function.

BACKGROUND

Depressive symptoms associated with higher risk of rehospitalisation have been primarily demonstrated in heart failure patients with systolic dysfunction (ejection fraction <40%) and the factors influencing rehospitalisation of patients with preserved systolic function (ejection fraction > or =40%) remain unclear.

DESIGN

A prospective, descriptive study design was used.

METHODS

The following baseline data were collected from 165 patients with preserved systolic function during an index hospitalisation for heart failure in South Korea: age, gender, body mass index, New York Heart Association functional class, the ratio of mitral velocity to early diastolic velocity of the mitral annulus, comorbidities, history of prior admission and depressive symptoms. Patients were followed monthly for six months after discharge to collect date on all rehospitalisation for heart failure exacerbation. Hierarchical Cox proportional hazards regression was used to identify independent predictors of rehospitalisation. Kaplan-Meier survival curves with log-rank test were used to determine differences in time to rehospitalisation according to severity of depressive symptoms.

RESULTS

Almost half of the patients (48%) had moderate to severe depressive symptoms. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (hazard ratio = 1.06, 95% confidence interval = 1.02-1.10) and depressive symptoms (hazard ratio = 1.05, 95% confidence interval = 1.02-1.08) independently predicted rehospitalisation after controlling for other risk factors. Moderate and severe depressive symptoms were associated with both a higher rate and shorter time to rehospitalisation.

CONCLUSIONS

Moderate to severe depressive symptoms predict early rehospitalisation for heart failure exacerbations in patients with preserved systolic function.

RELEVANCE TO CLINICAL PRACTICE

Nurses should assess for depressive symptoms in patients with heart failure and refer those with depressive symptoms for treatment to improve outcomes.

Usefulness of left ventricular diastolic dysfunction as a predictor of one-year rehospitalization in survivors of acute myocardial infarction

Presence of severe left ventricular (LV) diastolic function has been shown to independently predict risk of heart failure or death after acute myocardial infarction (AMI). We aimed to determine whether common echocardiographic parameters and (LV) diastolic function evaluated during AMI hospitalization can predict the risk of rehospitalization, up to 1 year after AMI. One hundred ninety consecutive patients with AMI, who were prospectively enrolled in a longitudinal post-AMI registry, had survived for 1 year, and had a clinically indicated echocardiogram during the index admission, were included in the study. The independent effect of diastolic dysfunction on 1-year all-cause rehospitalization was assessed using multivariable proportional hazards regression. Average age was 62.5 years, 93% were Caucasian, 66% were men, and mean LV ejection fraction was 46%. At 1 year, 78 patients (41%) had been rehospitalized >or=1 time. In multivariable analysis, presence of severe LV diastolic dysfunction was the only echocardiographic variable that predicted increased risk of rehospitalization 1 year after AMI (hazard ration 3.31, 95% confidence interval 1.26 to 8.69). Seventy-eight percent of patients with severe LV diastolic dysfunction (restrictive diastolic physiology) compared with 30% with normal diastolic function (p = 0.0052) and 37% with nonrestrictive physiology during the index admission were rehospitalized. In conclusion, severe LV diastolic dysfunction is the only echocardiographic predictor of rehospitalization in survivors of AMI and routine assessment of diastolic function during AMI hospitalization can provide additional prognostic risk stratification at dismissal.

Diastolic Dysfunction After an Acute Myocardial Infarction in Patients with Antecedent Hypertension

OBJECTIVE

We sought to assess changes in the left ventricular systolic and diastolic function in patients with antecedent hypertension and an acute myocardial infarction.

METHODS

A group of 38 patients with antecedent hypertension and acute myocardial infarction were compared with an age-matched nonhypertensive control group. There was a 30-day follow-up. Outcome measures were left ventricular volumes and ejection fraction, systolic velocities, and strain. Diastolic function was assessed by mitral inflow combined with tissue velocities of the mitral ring.

RESULTS

Patients with antecedent hypertension did not experience any regression in the E/E' ratio (16.5 +/- 7.5 vs 17.1 +/- 9.0, P = not significant) or increase in the E'/A' ratio (0.76 +/- 0.5 vs 0.84 +/- 0.6, P = not significant) compared with significant improvements in E/E' ratio (18.9 +/- 8.7 vs 12.8 +/- 7.4, P < .01) and E'/A' ratio (0.76 +/- 0.5 vs 1.1 +/- 0.7, P < .01) in the control group. This was found despite similar changes ejection fraction, volumes, and systolic strain.

CONCLUSIONS

Patients with antecedent hypertension have incomplete improvement of the diastolic function compared with control subjects despite comparable left ventricular volumes and ejection fraction after an acute myocardial infarction.

Epidemiology of heart failure and left ventricular dysfunction after acute myocardial infarction

The development of heart failure and/or left ventricular systolic dysfunction has long been regarded as an ominous complication, significantly increasing the morbidity and short- and long-term mortality of survivors of acute myocardial infarction. Although the incidence of heart failure after myocardial infarction has fallen over the last few decades, it remains common, complicating up to 45% of infarcts. Moreover, up to 60% of myocardial infarcts will result in left ventricular systolic dysfunction, depending on the exact definition used. Those at greatest risk of developing heart failure are the elderly, females, and those with prior myocardial infarction. Advances in the management of acute myocardial infarction have led to reduced in-hospital mortality (even when complicated by heart failure), but longer-term mortality remains high in these patients.

Aldosterone blockade in post-acute myocardial infarction heart failure

Development of heart failure (HF) or left ventricular systolic dysfunction (LVSD) significantly increases mortality post acute myocardial infarction (AMI). Aldosterone contributes to the development and progression of HF post AMI, and major guidelines now recommend aldosterone blockade in this setting. However, lack of practical experience with aldosterone blockade may make clinicians hesitant to use these therapies. This review is based on a consensus cardiology conference that occurred in May 2005 (New York City) concerning these topics. Potential barriers to the use of aldosterone blockade are discussed and an algorithm for appropriate in-hospital pharmacologic management of AMI with LVSD and/or HF is presented.

Left ventricular diastolic function following myocardial infarction

An acute myocardial infarction causes a loss of contractile fibers which reduces systolic function. Parallel to the effect on systolic function, a myocardial infarction also impacts diastolic function, but this relationship is not as well understood. The two physiologic phases of diastole, active relaxation and passive filling, are both influenced by myocardial ischemia and infarction. Active relaxation is delayed following a myocardial infarction, whereas left ventricular stiffness changes depending on the extent of infarction and remodeling. Interstitial edema and fibrosis cause an increase in wall stiffness which is counteracted by dilation. The effect on diastolic function is correlated to an increased incidence of adverse outcomes. Moreover, patients with comorbid conditions that are associated with worse diastolic function tend to have more adverse outcomes after infarction. There are currently no treatments aimed specifically at treating diastolic dysfunction following a myocardial infarction, but several new drugs, including aldosterone antagonists, may offer promise.

Epidemiology of heart failure and left ventricular systolic dysfunction after acute myocardial infarction: prevalence, clinical characteristics, and prognostic importance

The development of heart failure and/or left ventricular systolic dysfunction (LVSD) in the setting of acute myocardial infarction (AMI) results in significant risk far above that of AMI independently. In patients admitted to the hospital for AMI, concomitant heart failure and/or LVSD on hospital admission or development of either or both of these conditions during admission are among the strongest predictors of inhospital death and are associated with significant increases in inhospital, 30-day, and long-term mortality and rehospitalization rates. Given the high risks in this population, aggressive treatment, comprising early initiation and sustained use of evidence-based treatments, is essential for improving prognosis.

Therapies to prevent heart failure post-myocardial infarction

Heart failure (HF) is a common complication of myocardial infarction (MI) that carries a poor prognosis when present. HF and/or left ventricular systolic dysfunction (LVSD) occur in approximately 40% of patients who suffer acute MI. The estimated mortality of patients developing HF or LVSD post-MI is 20% to 30%, with that risk varying based on the presence of HF upon initial assessment versus occurring later during the MI hospitalization. Clinical factors and comorbidities associated with post-MI HF include age, diabetes, hypertension, female gender, infarct size, and tachycardia. Factors associated with decreased survival in patients with post-MI HF include Killip class, age, low blood pressure, tachycardia, male gender, and anterior location of MI. Despite extensive data identifying this patient population as high risk, patients with post-MI HF or LVSD are significantly less likely to receive evidence-based medications or revascularization procedures than those without HF. Despite the high prevalence of HF after MI, few studies have examined therapies to prevent it. This review summarizes studies that reported the incidence, risk factors, and outcomes of patients with post-MI HF or LVSD. Additionally, we discuss therapies to prevent post-MI HF and treatment of patients with post-MI HF and/or LVSD.

Different prognostic impact of systolic function in patients with heart failure and/or acute myocardial infarction

AIMS

To study the prognostic importance of left ventricular systolic function in patients with heart failure (HF) and acute myocardial infarction (AMI) with respect to the presence of prior heart failure and known ischemic heart disease.

METHODS

In 13,084 consecutive patients diagnosed with either AMI or HF, a medical history and an echocardiographic assessment of left ventricular systolic function by wall motion index (WMI) were obtained. Patients were divided into four groups: AMI with or without a history of HF, and primary HF (no recent AMI) with or without a history of ischemic heart disease (IHD). Mortality was assessed after nine years of follow-up.

RESULTS

WMI stratified patients according to all-cause mortality in all four groups of patients (p<0.0001). For a decrease in WMI of 0.3 (corresponding to a decrease in left ventricular ejection fraction of 0.1), the hazard ratio was 1.61 (95% CI: 1.48-1.76) for AMI patients without prior HF, 1.43 (1.38-1.48) for AMI patients with prior HF, 1.26 (1.22-1.30) for primary HF patients with IHD and 1.23 (1.18-1.27) for HF patients without IHD.

CONCLUSION

WMI stratifies patients with IHD and/or HF according to risk of all-cause death. The presence of HF attenuates the prognostic power of WMI.

Epidemiology and management of heart failure and left ventricular systolic dysfunction in the aftermath of a myocardial infarction

Robust epidemiological data on the incidence of myocardial infarction (MI) are hard to find, but synthesis of data from a number of sources indicates that the average hospital in the UK should admit about two patients with a first MI and one recurrent MI per 1000 population per year. Possibly the most relevant data on the incidence, prevalence, and persistence of post-MI heart failure can be derived from the TRACE study. Most patients will develop heart failure or major left ventricular systolic dysfunction (LVSD) at some time after an MI, most commonly during the index admission. In up to 20% of cases this will be transient, but such patients still have a poor prognosis. There is likely to be around one patient discharged per thousand population per year with heart failure or major LVSD after an acute MI. It is important to organise care structures to ensure that patients with post-MI heart failure and LVSD are identified and managed appropriately.