Influence of infarct-zone viability on left ventricular remodeling after acute myocardial infarction

Italian contributions to the history of acute myocardial infarction treatment

The reduction in mortality from cardiovascular disease has been one of the crowning achievements of medicine over the past century. The evolution in management of acute myocardial infarction (AMI) has played a key role. Yet, the epidemiology of patients with STEMI continues to evolve. The Global Registry of Acute Coronary Events (GRACE) documented that STEMI accounted for ~36% of ACS cases. According to an analysis of a large USA database, the age-adjusted and sex-adjusted incidence of hospitalizations for STEMI significantly decreased from 133 per 100,000 person-years in 1999 to 50 per 100,000 person-years in 2008. Despite advances in both the early management and longer-term treatment of AMI, this condition still represents a leading cause of morbidity and mortality in western countries, making essential understanding its determinants. Early mortality gains noted in all AMI patients may not be sustained over the longer term and reciprocal trends of decreasing mortality after AMI accompanied by an increasing incidence of heart failure have been demonstrated in more recent years. Greater salvage of high-risk MI patients in recent periods may contribute to these trends. Over the past century, insights into the pathophysiology of AMI revolutionized approaches to management through different historical phases. This review provides a historic perspective on the underlying discoveries and pivotal trials that have been the foundation of the key changes of pharmacological and interventional treatment of AMI leading to the dramatic improvement of prognosis during the last tre decades, with special emphasis to the Italian contributions to the field.

Determinants of Left Ventricular Systolic Function One Year after Primary Percutaneous Coronary Intervention for ST-elevation Myocardial Infarction in a Middle-Income Country

BACKGROUND

Little is known about the predictors of left ventricular ejection fraction (LVEF) -an important predictor of mortality- after primary percutaneous coronary intervention (PCI) in low- and middle-income countries.

METHODS

In a prospective cohort study at Imam Ali hospital, Kermanshah, Iran, we enrolled consecutive ST-elevation myocardial infarction (STEMI) patients treated with primary PCI (2016-2018) and followed them up to one year. LVEF levels were measured by echocardiography, at baseline and one-year follow-up. Determinants of preserved/improved LVEF were assessed using multi-variable logistic regression models.

RESULTS

Of 803 patients (mean age 58.53±11.7 years, 20.5% women), baseline LVEF levels of ≤35% were reported in 44%, 35- 50% in 40%, and ≥50% in 16% of patients. The mean ± SD of LVEF increased from 38.13%±9.2% at baseline to 41.49%±9.5% at follow-up. LVEF was preserved/improved in 629 (78.3%) patients. Adjusted ORs (95% CIs) for predictors of preserved/improved LVEF showed positive associations with creatinine clearance, 1.01 (1.00-1.02) and adherence to clopidogrel, 2.01 (1.33-3.02); and inverse associations with history of myocardial infarction (MI), 0.44 (0.25-0.78); creatine kinase MB (CK-MB), 0.997 (0.996- 0.999); door-balloon time (3rd vs. 1st tertile), 0.62 (0.39-0.98); number of diseased vessels (2 and 3 vs. 1: 0.63 (0.41-0.99) and 0.58 (0.36-0.93), respectively); and baseline LVEF (35-50% and ≥50% vs. ≤35%: 0.45 (0.28-0.71) and 0.19 (0.11-0.34), respectively).

CONCLUSION

Adherence to clopidogrel, short door-balloon time, high creatinine clearance, and lower baseline LVEF were associated with preserved/improved LVEF, while history of MI, high CK-MB, and multi-vessel disease were predictors of reduced LVEF. Long-term drug adherence should be considered for LVEF improvement in low- and middle-income countries.

Effect of Coronary Thrombus Aspiration in Non ST Elevation Acute Coronary Syndrome Patients on Three-Year Survival- Does it add any Benefit?

We assessed the effect of thrombus aspiration (TA) during percutaneous coronary intervention (PCI) on in-hospital and 3-year mortality in consecutive non-ST segment elevation myocardial infarction (n = 189) and unstable angina pectoris (n = 148) patients (n = 337) between 2011 and 2016. In total, 153 patients (45.4%) underwent TA. The number of patients with postoperative thrombolysis in terms of myocardial infarction grade 3 blood flow (P < .001) and myocardial blush grade 3 (P < .001) were significantly higher in all TA groups. At 6-, 12- and 24-month post-PCI, the mean left ventricular ejection fraction was significantly higher in the all TA groups versus the stand alone PCI group (P < .001). Thrombus aspiration was associated with a significant improvement both in epicardial flow, myocardial perfusion and left ventricular ejection fraction. Thrombus aspiration during PCI in all acute coronary syndrome (except ST segment elevation) patients was associated with better survival compared with stand alone PCI group at 3-year follow-up (P = .019).

Independent and cumulative association of clinical and morphological heart failure with long-term outcome after percutaneous coronary intervention

BACKGROUND

Heart failure (HF) is a risk factor for adverse post-procedural outcome after revascularization; however, it is unclear how left ventricular systolic dysfunction (LVSD) and clinical HF symptoms affect percutaneous coronary intervention (PCI) outcomes. We investigated the characteristics and long-term outcomes of patients with clinical HF or LVSD after PCI.

METHODS

This was a Japanese multicenter registry study of adult patients receiving PCI. Among 4689 consecutive patients who underwent PCI at 15 hospitals from January 2009 to December 2012, we analyzed 2634 (56.2%) with documented left ventricular ejection fraction (LVEF). They were divided into four groups based on clinical HF (symptoms or HF hospitalization) and LVEF [≥35% and <35% (HF due to LVSD)]. The primary outcome was major adverse cardiovascular events (MACE), comprising all-cause death, acute coronary syndrome, HF hospitalization, performance of coronary artery bypass grafting, and stroke within 2 years after the initial PCI.

RESULTS

Our findings revealed 354 patients (13.4%) with HF (clinical HF, n = 173, 48.9%; LVSD, n = 132, 37.3%; both, n = 49; 13.8%). The incidence of MACE was higher in patients with clinical HF or LVSD, and was largely due to higher non-cardiac death and HF hospitalization. After adjustment, clinical HF (hazard ratio 2.16, 95% confidence interval; 1.49-3.14) and lower LVEF (per 10%, hazard ratio 0.89, 95% confidence interval; 0.81-0.99) were independently associated with higher MACE risk.

CONCLUSIONS

Clinical HF and LVSD were independently associated with adverse long-term clinical outcomes, particularly with non-cardiac death and HF readmission, in patients treated with PCI.

Myocardial Contrast Uptake in Relation to Coronary Artery Disease and Prognosis

During left ventricular opacification (LVO), myocardial contrast uptake (MCU) is frequently observed, but its clinical implication is uncertain. We aimed to investigate the diagnostic performance of MCU and its prognostic value in known or suspected coronary artery disease (CAD). Contrast echocardiography was retrospectively analyzed in 457 patients who had previous coronary angiography <12 mo before LVO. MCU was classified into replacement or interstitial patterns. Subendocardial patterns were further inspected. Events were defined as a primary composite of the occurrence of acute coronary syndrome, heart failure hospitalization, sustained ventricular tachycardia and all-cause mortality. MCU had an 87.6% sensitivity, 75.5% specificity, 73.0% positive predictive value and 87.7% negative predictive value in detecting CAD. After a median follow-up of 17.3 mo, 52 events occurred. Replacement, interstitial and subendocardial MCU patterns were associated with events. In conclusion, the presence of MCU was useful in identifying CAD and provided incremental prognostic value for clinical outcomes.

Transmural difference in myocardial damage assessed by layer-specific strain analysis in patients with ST elevation myocardial infarction

We performed layer-specific strain analysis with speckle-tracking echocardiography to investigate the transmural difference of myocardial damage as the predicting factor for the viability of damaged myocardium in patients with ST segment elevation myocardial infarction (STEMI). We analysed patients with acute STEMI who had undergone primary percutaneous coronary intervention and echocardiography within 24 h from the intervention and 2 months after the event. Segmental strains of the left ventricular (LV) endocardium, myocardium, epicardium, and strain gradient (SG) between the endocardium and epicardium were evaluated. In 34 patients, 112 akinetic/dyskinetic and 94 hypokinetic segments were observed among 612 segments of the LV at baseline, and 65 akinetic/dyskinetic segments had viability. In our study, layer-specific strains were gradually deteriorated by their wall motion. SG was augmented in the hypokinetic segments where inhomogeneous wall motion impairment was progressed. SG in the akinetic/dyskinetic segments was different between the viable and non-viable myocardium and was maintained in viable segments. We therefore believe that significantly reduced SG is indicative of irreversible transmural damage in the acute stage of STEMI and can be suitably used as a parameter for predicting myocardial viability.

Evaluation of acute myocardial infarction patients with mid-range ejection fraction after emergency percutaneous coronary intervention

BACKGROUND

There is currently no classification for acute myocardial infarction (AMI) according to left ventricular ejection fraction (LVEF). We aimed to perform a retrospective analysis of patients undergoing emergency percutaneous coronary intervention (PCI), comparing the clinical characteristics, in-hospital acute heart failure and all-cause death events of AMI patients with mid-range ejection fraction (mrEF), preserved ejection fraction (pEF) and reduced ejection fraction (rEF).

MATERIAL AND METHODS

Totally 1270 patients were stratified according to their LVEF immediately after emergency PCI into pEF group (LVEF 50% or higher), mrEF group (LVEF 40%-49%) and rEF group (LVEF <40%). Kaplan-Meier curves and log rank tests were used to assess the effects of mrEF, rEF and pEF on the occurrence of acute heart failure and all-cause death during hospitalisation. The Cox proportional hazards model was used for multivariate correction.

RESULTS

Compared with mrEF, rEF was an independent risk factor for acute heart failure events during hospitalisation (HR 5.01, 95% CI 3.53 to 7.11, p<0.001), and it was also an independent risk factor for all-cause mortality during hospitalisation (HR 7.05, 95% CI 4.12 to 12.1, p<0.001); Compared with mrEF, pEF was an independent protective factor for acute heart failure during hospitalisation (HR 0.49, 95% CI 0.30 to 0.82, p=0.01), and it was also an independent protective factor for all-cause death during hospitalisation (HR 0.33, 95% CI 0.11 to 0.96, p=0.04).

CONCLUSIONS

mrEF patients with AMI undergoing emergency PCI share many similarities with pEF patients in terms of clinical features, but the prognosis is significantly worse than that of pEF patients, suggesting that we need to pay attention to the management of mrEF patients with AMI.

Pseudonormal or Restrictive Filling Pattern of Left Ventricle Predicts Poor Prognosis in Patients with Ischemic Heart Disease Presenting as Acute Heart Failure

BACKGROUND

In patients with acute heart failure (AHF), diastolic dysfunction, especially pseudonormal (PN) or restrictive filling pattern (RFP) of left ventricle (LV), is considered to be implicated in a poor prognosis. However, prognostic significance of diastolic dysfunction in patients with ischemic heart disease (IHD) has been rarely investigated in Korea.

METHODS

We enrolled 138 patients with IHD presenting as AHF and sinus rhythm during echocardiographic study. Diastolic dysfunction of LV was graded as ≥ 2 (group 1) or 1 (group 2) according to usual algorithm using E/A ratio and deceleration time of mitral inflow, E'/A' ratio of tissue Doppler echocardiography and left atrial size.

RESULTS

Patients in group 1 showed higher 2-year mortality rate (36.2% ± 6.7%) than those in group 2 (13.6% ± 4.5%; p = 0.008). Two-year mortality rate of patient with LV ejection fraction (LVEF) < 40% (26.8% ± 6.0%) was not different from those with LVEF 40%-49% (28.0% ± 8.0%) or ≥ 50% (13.7% ± 7.4%; p = 0.442). On univariate analysis, PN or RFP of LV, higher stage of chronic kidney disease (CKD) and higher New York Heart Association (NYHA) functional class were poor prognostic factors, but LVEF or older age ≥ 75 years did not predict 2-year mortality. On multivariate analysis, PN or RFP of LV (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.09-5.84; p = 0.031), higher stage of CKD (HR, 1.57; 95% CI, 1.14-2.17; p = 0.006) and higher NYHA functional class (HR, 1.81; 95% CI, 1.11-2.94; p = 0.017) were still significant prognostic factors for 2-year mortality.

CONCLUSIONS

PN or RFP of LV was a more useful prognostic factor for long-term mortality than LVEF in patients with IHD presenting as AHF.

Predictors of Left Ventricular Ejection Fraction Improvement After Primary Stenting in ST-Segment Elevation Myocardial Infarction (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction Trial)

The predictors of improvement in left ventricular ejection fraction (LVEF) after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) are poorly understood. We sought to determine the prevalence and clinical and angiographic predictors of LVEF improvement after primary PCI in STEMI. In the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction trial, 3,602 patients presenting with STEMI were randomized to heparin + a glycoprotein IIb/IIIa inhibitor versus bivalirudin. Routine 13-month angiographic follow-up was performed in a prespecified substudy of 656 stented patients. The median [25%, 75%] change in LVEF from baseline to 13 months was +2.4% [-5.9%, 11.8%]; LVEF increased or remained unchanged in 379 patients (57.8%; median Δ +9.8% [4.3%, 16.4%]) and fell in 277 patients (42.2%; median Δ -7.0% [-11.8%, -3.6%]). Independent predictors of LVEF improvement were female gender (p = 0.002), lower baseline LVEF (p <0.0001), Thrombolysis in Myocardial Infarction 3 flow after PCI (p = 0.03), shorter lesion length (p = 0.04), and lower post-PCI peak MB isoenzyme of creatine kinase (p <0.0001). In conclusion, in the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction trial, although LVEF improved during follow-up after primary PCI in more than half of patients, left ventricular function worsened over time in a substantial proportion, the occurrence of which may be predicted by clinical, angiographic, and laboratory variables.

Defining left ventricular remodeling following acute ST-segment elevation myocardial infarction using cardiovascular magnetic resonance

BACKGROUND

The assessment of post-myocardial infarction (MI) left ventricular (LV) remodeling by cardiovascular magnetic resonance (CMR) currently uses criteria defined by echocardiography. Our aim was to provide CMR criteria for assessing LV remodeling following acute MI.

METHODS

Firstly, 40 reperfused ST-segment elevation myocardial infarction (STEMI) patients with paired acute (4 ± 2 days) and follow-up (5 ± 2 months) CMR scans were analyzed by 2 independent reviewers and the minimal detectable changes (MDCs) for percentage change in LV end-diastolic volume (%ΔLVEDV), LV end-systolic volume (%ΔLVESV), and LV ejection fraction (%ΔLVEF) between the acute and follow-up scans were determined. Secondly, in 146 reperfused STEMI patients, receiver operator characteristic curve analyses for predicting LVEF <50% at follow-up (as a surrogate for clinical poor clinical outcome) were undertaken to obtain cut-off values for %ΔLVEDV and %ΔLVESV.

RESULTS

The MDCs for %ΔLVEDV, %ΔLVESV, and %ΔLVEF were similar at 12%, 12%, 13%, respectively. The cut-off values for predicting LVEF < 50% at follow-up were 11% for %ΔLVEDV on receiver operating characteristic curve analysis (area under the curve (AUC) 0.75, 95% CI 0.6 to 0.83, sensitivity 72% specificity 70%), and 5% for %ΔLVESV (AUC 0.83, 95% CI 0.77 to 0.90, sensitivity and specificity 78%). Using cut-off MDC values (higher than the clinically important cut-off values) of 12% for both %ΔLVEDV and %ΔLVESV, 4 main patterns of LV remodeling were identified in our cohort: reverse LV remodeling (LVEF predominantly improved); no LV remodeling (LVEF predominantly unchanged); adverse LV remodeling with compensation (LVEF predominantly improved); and adverse LV remodeling (LVEF unchanged or worsened).

CONCLUSIONS

The MDCs for %ΔLVEDV and %ΔLVESV between the acute and follow-up CMR scans of 12% each may be used to define adverse or reverse LV remodeling post-STEMI. The MDC for %ΔLVEF of 13%, relative to baseline, provides the minimal effect size required for investigating treatments aimed at improving LVEF following acute STEMI.

Manual Thrombus Aspiration and the Improved Survival of Patients With Unstable Angina Pectoris Treated With Percutaneous Coronary Intervention (30 Months Follow-Up)

The clinical effect of intracoronary thrombus aspiration during percutaneous coronary intervention in patients with unstable angina pectoris is unknown. In this study, we aimed to assess how thrombus aspiration during percutaneous coronary intervention affects in-hospital and 30-month mortality and complications in patients with unstable angina pectoris.We undertook an observational cohort study of 645 consecutive unstable angina pectoris patients who had performed percutaneous coronary intervention from February 2011 to March 2013. Before intervention, 159 patients who had culprit lesion with thrombus were randomly assigned to group 1 (thrombus aspiration group) and group 2 (stand-alone percutaneous coronary intervention group). All patients were followed-up 30 months until August 2015.Thrombus aspiration was performed in 64 patients (46%) whose cardiac markers (ie, creatinine kinase [CK-MB] mass and troponin T) were significantly lower after percutaneous coronary intervention than in those of group 2 (CK-MB mass: 3.80 ± 1.11 vs 4.23 ± 0.89, P = 0.012; troponin T: 0.012 ± 0.014 vs 0.018 ± 0.008, P = 0.002). Left ventricular ejection fraction at 6, 12, and 24 months postintervention was significantly higher in the group 1. During a mean follow-up period of 28.87 ± 6.28 months, mortality rates were 6.3% in the group 1 versus 12.9% in the group 2. Thrombus aspiration was also associated with significantly less long-term mortality in unstable angina pectoris patients (adjusted HR: 4.61, 95% CI: 1.16-18.21, P = 0.029).Thrombus aspiration in the context of unstable angina pectoris is associated with a limited elevation in cardiac enzymes during intervention that minimises microembolization and significantly improves both of epicardial flow and myocardial perfusion, as shown by angiographic TIMI flow grade and frame count. Thrombus aspiration during percutaneous coronary intervention in unstable angina pectoris patients has better survival over a 30-month follow-up period.

Predictors of ventricular remodelling in patients with reperfused acute myocardial infarction and left ventricular dysfunction candidates for bone marrow cell therapy: insights from the BONAMI trial

PURPOSE

Few data are available regarding the relation of left ventricular (LV) mechanical dyssynchrony to remodelling after acute myocardial infarction (MI) and stem cell therapy. We evaluated the 1-year time course of both LV mechanical dyssynchrony and remodelling in patients enrolled in the BONAMI trial, a randomized, multicenter controlled trial assessing cell therapy in patients with reperfused MI.

METHODS

Patients with acute MI and ejection fraction (EF) ≤ 45 % were randomized to cell therapy or to control and underwent thallium single-photon emission computed tomography (SPECT), radionuclide angiography, and echocardiography at baseline, 3 months, and 1 year. Eighty-three patients with a comprehensive 1-year follow-up were included. LV dyssynchrony was assessed by the standard deviation (SD) of the LV phase histogram using radionuclide angiography. Remodelling was defined as a 20 % increase in LV end-systolic volume index (LVESVI) at 1 year.

RESULTS

At baseline, LVEF, wall motion score index, and perfusion defect size were significantly impaired in the 43 patients (52 %) with LV remodelling (all p < 0.001), without significant increase in LV mechanical dyssynchrony. During follow-up, there was a progressive increase in LV SD (p = 0.01). Baseline independent predictors of LV remodelling were perfusion SPECT defect size (p = 0.001), LVEF (p = 0.01) and a history of hypertension (p = 0.043). Bone marrow cell therapy did not affect the time-course of LV remodelling and dyssynchrony.

CONCLUSIONS

LV remodelling 1 year after reperfused MI is associated with progressive LV dyssynchrony and is related to baseline infarct size and ejection fraction, without impact of cell therapy on this process.

The Relationship among N-Terminal Pro-B-Type Natriuretic Peptide, High-Sensitivity C-Reactive Protein and Infarct Size in Patients with Acute ST-Elevation Myocardial Infarction

Background and Objectives

We sought to investigate the relationship between levels of high-sensitivity C-reactive protein (hs-CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and the infarct size and left ventricular (LV) volume after acute myocardial infarction (MI).

Subjects and Methods

Eighty-six patients with acute ST-elevation MI underwent delayed enhancement multidetector computed tomography immediately after they underwent percutaneous coronary intervention to determine the infarct size. LV function and remodeling were assessed by echocardiography. Hs-CRP and NT-proBNP were measured at admission, 24 hours and two months later.

Results

Both hs-CRP and NT-proBNP at 24 hours showed a positive correlation with infarct size and a negative correlation with LV ejection fraction at the baseline and two months later. NT-proBNP at two months correlated with infarct size, LV ejection fraction, and LV end diastolic and systolic volume indices at two months. In patients with high NT-proBNP levels at 24 hours and two months, infarct size was larger and LV ejection fraction was lower. NT-proBNP was higher in patients who developed LV remodeling at two months: 929 pg/mL vs. 134 pg/mL, p=0.002. In contrast, hs-CRP at two months showed no relationship to infarct size, LV function, or LV volumes at two months.

Conclusion

Elevated hs-CRP level 24 hours after the onset of acute MI is associated with infarct size and LV dysfunction, whereas elevated levels of NT-proBNP 24 hours and two months after the onset of acute MI are both correlated with infarct size, LV dysfunction, and LV remodeling.

Two-dimensional speckle-tracking echocardiography assessment of left ventricular remodeling in patients after myocardial infarction and primary reperfusion

INTRODUCTION

Left ventricular remodeling (LVR) is the most prognostically important consequence of acute myocardial infarction (AMI). The aim of the study was to assess the value of speckle tracking echocardiography in the prediction of left ventricular remodeling in patients after AMI and primary coronary angioplasty (PCI).

MATERIAL AND METHODS

Eighty-eight patients (F/M = 31/57 patients; 63.6 ±11 years old) with coronary artery disease (CAD) and successful PCI were enrolled and divided into group I with ST-elevation myocardial infarction or non-ST elevation myocardial infarction and group II with stable angina pectoris. Conventional and speckle tracking echocardiography was performed 3 days (baseline), 30 days and 90 days after PCI. Patients were divided into 2 groups based on the presence of LVR (increase of LV end-diastolic and/or end-systolic volume > 20%) at 3 months follow-up.

RESULTS

At initial presentation, 2-chamber longitudinal strain (9.4 ±3.5% vs. -11.6 ±3.6%, p < 0.04) and 4-chamber transverse strain (10.4 ±8.2% vs. 15.6 ±8%, p < 0.003) were lower in the LVR+ group compared to the LVR- group. LV wall motion score index did not differ between the two groups. After 30 days, circumferential apical and basal strain (-15.58 ±8.9% vs. -25.53 ±8.8%, p < 0.001; -15.02 ±5.6 vs. -19.78 ±6.3, p < 0.008), radial apical strain (9.96 ±8.4% vs. 14.15 ±5.5%, p < 0.03), 4-chamber longitudinal strain (-8.7 ±5.8% vs. -13.47 ±3.9%, p < 0.005), 4-chamber transverse strain (10.5 ±8.1% vs. 16.7 ±8.3%, p < 0.03), apical rotation (3.84 ±2.5° vs, 5.66 ±3.2°, p < 0.04) and torsion (6.15 ±4.1° vs. 8.98 ±4.6°, p < 0.03) were significantly decreased in the LVR+ group compared to the LVR- group. According to ROC analysis, circumferential apical strain > -15.92% (sensitivity 93%, specificity 59%, positive predictive value 90%) was the most powerful predictor of remodeling after primary PCI in AMI.

CONCLUSIONS

Our results suggest that impaired indices of LV deformation detected 3 days and 30 days after AMI may provide important predictive value in LV remodeling and patients' follow-up.

Prognostic Value of Speckle Tracking Echocardiography in Patients with ST-Elevation Myocardial Infarction Treated with Late Percutaneous Intervention

BACKGROUND

Left ventricular remodeling (LVr) is common after ST-segment elevation myocardial infarction (STEMI). The aim of this study was to evaluate the prognostic value of speckle tracking echocardiography (STE) for predicting LVr 6-9 months after late percutaneous coronary intervention (PCI) in patients with STEMI.

METHODS

Patients with first STEMI who accepted late PCI were enrolled. Echocardiography was performed within 48 hours of admission. Six to nine months after MI, an echocardiography examination was repeated. LVr was defined as >15% increase in LV end-systolic volume (LVESV) after 6 months.

RESULTS

One hundred and twenty-seven patients were divided into two groups: 86 patients without LVr and 41 patients with LVr. There were significant differences in the global longitudinal strain (GLS), SD of time to peak longitudinal systolic strain (longitudinal Ts-SD), longitudinal postsystolic index, radial strain (RS), and SD of time to peak radial systolic strain (Radial Ts-SD). In multivariate logistic regression analysis, the GLS(odds ratio [OR] = 0.39, 95% confidence interval [CI] = 0.26-0.57, P < 0.01), and RS(OR = 1.07, 95% CI = 1.02-1.13, P = 0.01) were determinants of LVr. A receiver operating characteristic curve showed that the GLS predicted LVr with an optimal cutoff value of -10.85 (sensitivity: 89.7%, specificity: 91.7%). During clinical follow-up for 16.9 ± 1.6 months, death or congestive heart failure developed in 12 patients (9.4%), and the baseline ejection fraction (OR = 1.91, 95% CI = 1.18-3.1, P = 0.009) and GLS (OR = 0.56, 95% CI = 0.34-0.91, P = 0.02) were independent predictors.

CONCLUSION

In patients with STEMI treated with late percutaneous coronary intervention, the GLS as measured by STE is a strong predictor of LVr and adverse events.

Left ventricular remodeling after acute myocardial infarction: the influence of viability and revascularization - an echocardiographic substudy of the VIAMI-trial

BACKGROUND

Viability seems to be important in preventing ventricular remodeling after acute myocardial infarction (AMI). We investigated the influence of viability, as demonstrated with low-dose dobutamine echocardiography, and the role of early revascularization on the process of left ventricular (LV) remodeling after AMI.

METHODS

We retrospectively investigated 224 patients who were initially included in the viability-guided angioplasty after acute myocardial infarction-trial (VIAMI-trial). Patients in the VIAMI-trial did not undergo a primary or rescue percutaneous coronary intervention and were stable in the early in-hospital phase. Patients underwent viability testing within 72 hours after AMI. Patients with viability were randomized to an invasive strategy or an ischemia-guided strategy. Follow-up echocardiography was performed at a mean of 205 days. In this echocardiographic substudy, patients were divided into three new groups: group 1, viable and revascularized before follow-up echocardiogram; group 2, viable, but medically treated; and group 3, non-viable patients.

RESULTS

Group 1 showed preservation of LV volume indices. The ejection fraction (EF) increased significantly from 54.0% to 57.5% (P = 0.047). Group 2 showed a significant increase in LV volume indices with no improvement in EF (53.3% versus 53.0%, P = 0.86). Group 3 showed a significant increase in LV volume indices, with a decrease in EF from 53.5% to 49.1% (P = 0.043). Multivariate logistic regression analysis indicated the number of viable segments and revascularization during follow-up as independent predictors for EF improvement, especially in patients with lower EF at baseline.

CONCLUSION

Viability early after AMI is associated with improvement in LV function after revascularization. When viable myocardium is not revascularized, the LV tends to remodel with increased LV volumes, without improvement of EF. Absence of viability results in ventricular dilatation and deterioration of EF, irrespective of revascularization status.

TRIAL REGISTRATION

NCT00149591 (assigned: 6 September 2005).

Left ventricular remodeling after late revascularization correlates with baseline viability

The ideal management of stable patients who present late after acute ST-elevation myocardial infarction (STEMI) is still a matter of conjecture. We hypothesized that the extent of improvement in left ventricular function after successful revascularization in this subset was related to the magnitude of viability in the infarct-related artery territory. However, few studies correlate the improvement of left ventricular function with the magnitude of residual viability in patients who undergo percutaneous coronary intervention in this setting. In 68 patients who presented later than 24 hours after a confirmed first STEMI, we performed resting, nitroglycerin-enhanced, technetium-99m sestamibi single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) before percutaneous coronary intervention, and again 6 months afterwards. Patients whose baseline viable myocardium in the infarct-related artery territory was more than 50%, 20% to 50%, and less than 20% were divided into Groups 1, 2, and 3 (mildly, moderately, and severely reduced viability, respectively). At follow-up, there was significant improvement in end-diastolic volume, end-systolic volume, and left ventricular ejection fraction in Groups 1 and 2, but not in Group 3. We conclude that even late revascularization of the infarct-related artery yields significant improvement in left ventricular remodeling. In patients with more than 20% viable myocardium in the infarct-related artery territory, the extent of improvement in left ventricular function depends upon the amount of viable myocardium present. The SPECT-MPI can be used as a guide for choosing patients for revascularization.

Growth properties of cardiac stem cells are a novel biomarker of patients' outcome after coronary bypass surgery

BACKGROUND

The efficacy of bypass surgery in patients with ischemic cardiomyopathy is not easily predictable; preoperative clinical conditions may be similar, but the outcome may differ significantly. We hypothesized that the growth reserve of cardiac stem cells (CSCs) and circulating cytokines promoting CSC activation are critical determinants of ventricular remodeling in this patient population.

METHODS AND RESULTS

To document the growth kinetics of CSCs, population-doubling time, telomere length, telomerase activity, and insulin-like growth factor-1 receptor expression were measured in CSCs isolated from 38 patients undergoing bypass surgery. Additionally, the blood levels of insulin-like growth factor-1, hepatocyte growth factor, and vascular endothelial growth factor were evaluated. The variables of CSC growth were expressed as a function of the changes in wall thickness, chamber diameter and volume, ventricular mass-to-chamber volume ratio, and ejection fraction, before and 12 months after surgery. A high correlation was found between indices of CSC function and cardiac anatomy. Negative ventricular remodeling was not observed if CSCs retained a significant growth reserve. The high concentration of insulin-like growth factor-1 systemically pointed to the insulin-like growth factor-1-insulin-like growth factor-1 receptor system as a major player in the adaptive response of the myocardium. hepatocyte growth factor, a mediator of CSC migration, was also high in these patients preoperatively, as was vascular endothelial growth factor, possibly reflecting the vascular growth needed before bypass surgery. Conversely, a decline in CSC growth was coupled with wall thinning, chamber dilation, and depressed ejection fraction.

CONCLUSIONS

The telomere-telomerase axis, population-doubling time, and insulin-like growth factor-1 receptor expression in CSCs, together with a high circulating level of insulin-like growth factor-1, represent a novel biomarker able to predict the evolution of ischemic cardiomyopathy following revascularization.

Low-dose dobutamine adds incremental value to late gadolinium enhancement cardiac magnetic resonance in the prediction of adverse remodelling following acute myocardial infarction

AIMS

To examine the relative and combined value of late gadolinium enhancement (LGE) and low-dose dobutamine (LDD) cardiac magnetic resonance (CMR) to predict 'adverse remodelling' (AR) following acute myocardial infarction (AMI).

METHODS AND RESULTS

Forty-five patients with AMI were recruited. CMR was performed 2-4 days after presentation and at 6 months. Ventricular wall motion and volume were recorded at rest and following dobutamine infusion. Measures of first pass perfusion, persistent microvascular obstruction (PMO), and LGE were obtained following contrast administration. Quantitation was performed using the MEDIS 6.2 software. Regression analysis was employed to determine the univariables and multivariate models most predictive of AR at 6 months. The incremental and relative value of LDD over LGE was investigated. The most predictive univariable was 'volume of PMO' (r = 0.51, r2 = 0.26, P < 0.001). The optimal 'combined' multivariate model, utilizing data from all components, was highly predictive of AR (r = 0.82, r2 = 0.67, P < 0.001). The optimal model using parameters only from the LGE component also predicted remodelling (r = 0.65, r2 = 42.0, P = 0.001) but with less accuracy. In contrast, the optimal model using variables from the LDD component alone predicted remodelling with a similar accuracy to the optimal combined model (r = 0.82, r2 = 0.67, P < 0.001).

CONCLUSION

A comprehensive CMR examination accurately predicts AR following AMI. LDD is superior to LGE CMR in this respect. These data suggest that LDD not only adds incremental value to LGE in the prediction of remodelling post-AMI but also may be utilized alone with the same predictive power.

Predictors of recovery of left ventricular systolic dysfunction after acute myocardial infarction: from the korean acute myocardial infarction registry and korean myocardial infarction registry

Background and Objectives

We investigated the predictors of the recovery of depressed left ventricular ejection fraction (LVEF) in patients with moderate or severe left ventricular (LV) systolic dysfunction after acute myocardial infarction (MI).

Subjects and Methods

We analyzed 1307 patients, who had moderately or severely depressed LVEF (<45%) on echocardiography soon after acute MI and who underwent a follow-up echocardiography, among 27369 patients from the Korea Working Group on the Myocardial Infarction Registry. Patients were categorized into two groups according to recovery of LVEF: group I with consistently depressed LVEF (<45%) at the follow-up echocardiography and group II with a recovery of LVEF (≥45%).

Results

Recovery of LV systolic dysfunction was observed in 51% of the subjects (group II, n=663; ΔLVEF, 16.2±9.3%), whereas there was no recovery in the remaining subjects (group I, n=644; ΔLVEF, 0.6±7.1%). In the multivariate analysis, independent predictors of recovery of depressed LVEF were as follows {odds ratio (OR) [95% confidence interval (CI)]}: moderate systolic dysfunction {LVEF ≥30% and <45%; 1.73 (1.12-2.67)}, Killip class I-II {1.52 (1.06-2.18)}, no need for diuretics {1.59 (1.19-2.12)}, non-ST-segment elevation MI {1.55 (1.12-2.16)}, lower peak troponin I level {<24 ng/mL, median value; 1.55 (1.16-2.07)}, single-vessel disease {1.53 (1.13-2.06)}, and non-left anterior descending (LAD) culprit lesion {1.50 (1.09-2.06)}. In addition, the use of statin was independently associated with a recovery of LV systolic dysfunction {OR (95% CI), 1.46 (1.07-2.00)}.

Conclusion

Future contractile recovery of LV systolic dysfunction following acute MI was significantly related with less severe heart failure at the time of presentation, a smaller extent of myonecrosis, or non-LAD culprit lesions rather than LAD lesions.

Prognostic value of reverse left ventricular remodeling after primary angioplasty for STEMI

AIMS

Thus far, the prognostic value of reverse left ventricular (LV) remodeling after ST-elevation acute myocardial infarction (STEMI) has not been fully evaluated. We sought to investigate the incidence, major determinants, and long-term clinical significance of reverse LV remodeling in a large series of STEMI patients successfully treated with primary percutaneous coronary intervention (P-PCI).

METHODS AND RESULTS

Serial complete 2D-echocardiograms were obtained within 24h after P-PCI, and at 1 and 6 months in 512 consecutive reperfused STEMI patients. Reverse remodeling was defined as a reduction >10% in LV end-systolic volume (LVESV) at 6 month follow-up. Reverse LV remodeling occurred in 49% of study population. At follow-up (41.6±23 months), late heart failure (HF) rate was significantly higher among patients without reverse LV remodeling as compared with those with it (32% vs. 11%, P<0.0001). At multivariate analysis, independent predictors of reverse LV remodeling were a small infarct size measured as peak creatine kinase value (P<0.0001), a small functional myocardial damage measured as wall motion score index within the infarct zone (P=0.018) and baseline LVESV (P<0.0001). After adjustment for several clinical, echographic and angiographic variables, Cox analysis identified reverse LV remodeling as the only beneficial independent predictor of long-term heart failure-free survival (HR: 0.44, 95% CI: 0.275-0.722).

CONCLUSIONS

Reverse LV remodeling occurred in half of successfully reperfused STEMI patients. Small structural and functional myocardial damages within the infarct zone are the major determinants of reverse LV remodeling. As expression of effective myocardial salvage by P-PCI, the reverse remodeling is an important predictor of favorable long-term outcome.

Computational protein design to reengineer stromal cell-derived factor-1α generates an effective and translatable angiogenic polypeptide analog

BACKGROUND

Experimentally, exogenous administration of recombinant stromal cell-derived factor-1α (SDF) enhances neovasculogenesis and cardiac function after myocardial infarction. Smaller analogs of SDF may provide translational advantages including enhanced stability and function, ease of synthesis, lower cost, and potential modulated delivery via engineered biomaterials. In this study, computational protein design was used to create a more efficient evolution of the native SDF protein.

METHODS AND RESULTS

Protein structure modeling was used to engineer an SDF polypeptide analog (engineered SDF analog [ESA]) that splices the N-terminus (activation and binding) and C-terminus (extracellular stabilization) with a diproline segment designed to limit the conformational flexibility of the peptide backbone and retain the relative orientation of these segments observed in the native structure of SDF. Endothelial progenitor cells (EPCs) in ESA gradient, assayed by Boyden chamber, showed significantly increased migration compared with both SDF and control gradients. EPC receptor activation was evaluated by quantification of phosphorylated AKT, and cells treated with ESA yielded significantly greater phosphorylated AKT levels than SDF and control cells. Angiogenic growth factor assays revealed a distinct increase in angiopoietin-1 expression in the ESA- and SDF-treated hearts. In addition, CD-1 mice (n=30) underwent ligation of the left anterior descending coronary artery and peri-infarct intramyocardial injection of ESA, SDF-1α, or saline. At 2 weeks, echocardiography demonstrated a significant gain in ejection fraction, cardiac output, stroke volume, and fractional area change in mice treated with ESA compared with controls.

CONCLUSIONS

Compared with native SDF, a novel engineered SDF polypeptide analog (ESA) more efficiently induces EPC migration and improves post-myocardial infarction cardiac function and thus offers a more clinically translatable neovasculogenic therapy.

The Occluded Artery Trial (OAT) Viability Ancillary Study (OAT-NUC): influence of infarct zone viability on left ventricular remodeling after percutaneous coronary intervention versus optimal medical therapy alone

BACKGROUND

The Occluded Artery Trial (OAT) showed no difference in outcomes between percutaneous coronary intervention (PCI) versus optimal medical therapy (MED) in patients with persistent total occlusion of the infarct-related artery 3 to 28 days post-myocardial infarction. Whether PCI may benefit a subset of patients with preservation of infarct zone (IZ) viability is unknown.

METHODS AND RESULTS

The OAT nuclear ancillary study hypothesized that (1) IZ viability influences left ventricular (LV) remodeling and that (2) PCI as compared with MED attenuates adverse remodeling in post-myocardial infarction patients with preserved viability. Enrolled were 124 OAT patients who underwent resting nitroglycerin-enhanced technetium-99m sestamibi single-photon emission computed tomography (SPECT) before OAT randomization, with repeat imaging at 1 year. All images were quantitatively analyzed for infarct size, IZ viability, LV volumes, and function in a core laboratory. At baseline, mean infarct size was 26% ± 18 of the LV, mean IZ viability was 43% ± 8 of peak uptake, and most patients (70%) had at least moderately retained IZ viability. There were no significant differences in 1-year end-diastolic or end-systolic volume change between those with severely reduced versus moderately retained IZ viability, or when compared by treatment assignment PCI versus MED. In multivariable models, increasing baseline viability independently predicted improvement in ejection fraction (P = .005). There was no interaction between IZ viability and treatment assignment for any measure of LV remodeling.

CONCLUSIONS

In the contemporary era of MED, PCI of the infarct-related artery compared with MED alone does not impact LV remodeling irrespective of IZ viability.

Oxygen-dependent quenching of phosphorescence used to characterize improved myocardial oxygenation resulting from vasculogenic cytokine therapy

This study evaluates a therapy for infarct modulation and acute myocardial rescue and utilizes a novel technique to measure local myocardial oxygenation in vivo. Bone marrow-derived endothelial progenitor cells (EPCs) were targeted to the heart with peri-infarct intramyocardial injection of the potent EPC chemokine stromal cell-derived factor 1α (SDF). Myocardial oxygen pressure was assessed using a noninvasive, real-time optical technique for measuring oxygen pressures within microvasculature based on the oxygen-dependent quenching of the phosphorescence of Oxyphor G3. Myocardial infarction was induced in male Wistar rats (n = 15) through left anterior descending coronary artery ligation. At the time of infarction, animals were randomized into two groups: saline control (n = 8) and treatment with SDF (n = 7). After 48 h, the animals underwent repeat thoracotomy and 20 μl of the phosphor Oxyphor G3 was injected into three areas (peri-infarct myocardium, myocardial scar, and remote left hindlimb muscle). Measurements of the oxygen distribution within the tissue were then made in vivo by applying the end of a light guide to the beating heart. Compared with controls, animals in the SDF group exhibited a significantly decreased percentage of hypoxic (defined as oxygen pressure ≤ 15.0 Torr) peri-infarct myocardium (9.7 ± 6.7% vs. 21.8 ± 11.9%, P = 0.017). The peak oxygen pressures in the peri-infarct region of the animals in the SDF group were significantly higher than the saline controls (39.5 ± 36.7 vs. 9.2 ± 8.6 Torr, P = 0.02). This strategy for targeting EPCs to vulnerable peri-infarct myocardium via the potent chemokine SDF-1α significantly decreased the degree of hypoxia in peri-infarct myocardium as measured in vivo by phosphorescence quenching. This effect could potentially mitigate the vicious cycle of myocyte death, myocardial fibrosis, progressive ventricular dilatation, and eventual heart failure seen after acute myocardial infarction.

Left ventricular remodeling after primary percutaneous coronary intervention

Left ventricular (LV) remodeling has been shown to occur in a relevant proportion of patients with acute myocardial infarction successfully treated with primary percutaneous coronary intervention. The development of LV remodeling after primary percutaneous coronary intervention is associated with increased mortality and with shorter event-free survival. Therapy to prevent or limit LV remodeling is of paramount importance, and it should be started in the early phase of reperfusion. Early identification of patients at risk for LV remodeling may have important prognostic and therapeutic implications. The pathophysiology, time course, and predictors of LV remodeling, as well as the relevant diagnostic techniques and therapeutic interventions evaluated to date, will be discussed.

Left ventricular remodeling in the elderly with acute anterior myocardial infarction treated with primary coronary intervention

We compared left ventricular (LV) remodeling following a first time acute anterior ST-elevation myocardial infarction (aSTEMI) treated with primary coronary intervention (pPCI) in different age groups. A total of 116 patients, 61 aged <65 and 55 aged >or=65 years, who survived after a recent aSTEMI treated with pPCI, underwent dobutamine stress-echocardiography (DSE) and non-invasive measurement of left anterior descending coronary artery flow reserve (CFR) during intravenous adenosine infusion. Baseline LV dimensions and systolic function were similar between the two groups; wall motion score indices during all DSE stages and CFR were also similar. In both groups, the LV ejection fraction was positively affected by the presence of viability in the necrosis area and by a higher CFR, but negatively influenced by viability in a remote area, an indirect sign of an extensive infarction size. This study demonstrates that PCI in the geriatric population with aSTEMI is as equally effective as in younger subjects, in terms of LV remodeling and function.

Comparison of effects of primary coronary angioplasty on left ventricular remodeling and heart failure in patients <70 versus > or =70 years with acute myocardial infarction

Experimental studies have demonstrated the adverse effects of senescence on cardiac function and remodeling after acute myocardial infarction (AMI). We sought to assess the impact of age on left ventricular (LV) remodeling and heart failure (HF) after successful primary angioplasty for AMI. A series of 512 consecutive patients underwent 2-dimensional echocardiography at admission and at 1 month and 6 months after index AMI. LV volumes, ejection fraction, and wall motion score index (WMSI) were measured. Patients were divided in group 1 (<70 years old, n = 361) and group 2 (> or =70 years old, n = 151). Group 2 patients showed a lower peak creatine kinase (p = 0.029) compared to group 1. In group 2 patients the 6-month prevalence of LV remodeling (increase >20% in end-diastolic volume) was higher (34% vs 25%, p = 0.041), recoveries of ejection fraction and WMSI were lower (p = 0.00002 for the 2 comparisons), and incidence of late HF was higher (35% vs 17%, p <0.0001) compared to group 1 patients. Independent predictors of LV remodeling were WMSI (p <0.0001), infarct size (p <0.0001), and LV end-diastolic volume (p <0.0001). Independent predictors of late HF were WMSI (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.624 to 4.514), 6-month LV dilation (HR 2.13, 95% CI 1.404 to 3.233), diabetes (HR 1.6, 95% CI 1.008 to 2.595), infarct size (HR 1.12, 95% CI 1.037 to 1.215), and age as continuous variables (HR 1.064, 95% CI 1.044 to 1.085). In conclusion, besides infarct size, extensive regional systolic dysfunction may play a significant role in the development of LV remodeling and HF in patients > or =70 years old after successful primary angioplasty.

Rest and low-dose dobutamine Tc-99m-mibi gated-SPECT for early prediction of left ventricular remodeling after a first reperfused myocardial infarction

BACKGROUND

Left ventricular (LV) remodeling after myocardial infarction (MI) occurs frequently despite successful percutaneaous coronary intervention (PCI) but cannot be predicted by simple clinical parameters.

METHODS AND RESULTS

This prospective study tested the value of rest and low-dose dobutamine (LDD) Tc-99m-mibi gated-SPECT for early prediction of LV remodeling in patients treated by PCI in the acute phase of a first MI. Infarct size, infarct severity, regional wall motion abnormality (RWMA), and wall thickening score (WTs) were assessed at rest and on LDD by SPECT 6 +/- 2 days after MI in 40 patients. LV remodeling was defined as 20% increase at 6 months in LV end-diastolic volume assessed by MRI. Infarct severity at rest showed the best predictive values for left remodeling (PPV: 86%, NPV: 88%, accuracy: 88%; AUC: 0.750). Functional parameters at neither rest nor LDD study further improved predictive values of the SPECT imaging.

CONCLUSIONS

Infarct severity assessed by Tc-99m-sestamibi gated-SPECT performed in the subacute phase of a first STEMI predicts LV remodeling with high accuracy without incremental value nor of functional parameters nor of LDD. Therefore, our results suggest that LDD should not be used in this setting.

Left ventricular systolic dyssynchrony is a predictor of cardiac remodeling after myocardial infarction

OBJECTIVES

We sought to determine whether early assessment of left ventricular (LV) dyssynchrony by tissue Doppler imaging may predict progressive ventricular enlargement and cardiac dysfunction after acute myocardial infarction (MI).

METHODS

Forty-seven patients (mean age 59.9 +/- 11.6 years) with normal QRS duration underwent tissue Doppler imaging and contrast-enhanced cardiac magnetic resonance imaging (Ce-MRI) at days 2 to 6, 3 months, and at 1 year after the index MI. Systolic dyssynchrony index (Ts-SD) was calculated from 12 LV segments, and infarct size (IS) by Ce-MRI.

RESULTS

The remodeling group (n = 16) (defined as an increase in end-systolic volume > or =10% between 1 year and baseline) had greater initial IS (27.2 +/- 9.6 vs 13.7 +/- 4.1%, P < .001) and Ts-SD (50.9 +/- 12.8 vs 33.6 +/- 7.7 milliseconds, P < .001) than nonremodeling group (n = 31). At 1 year, the remodeling group had progressive increase in Ts-SD and decrease in LV ejection fraction (57.3 +/- 18.5 and 36.0 +/- 7.6%, respectively; both P < .05 vs baseline). Both Ts-SD (odds ratio 1.19 [1.07-1.32], P = .001) and IS (odds ratio 1.65 [1.19-2.29], P = .003) were shown to be independent predictors of progressive LV remodeling. A cutoff value of Ts-SD > or =45 milliseconds predicted LV remodeling at 1 year (sensitivity 90.5%, specificity 90.9%, Area-under-curve 0.907) (P = .0005).

CONCLUSIONS

Left ventricular systolic dyssynchrony is a newly identified predictor of chronic LV remodeling after acute MI, which is independent and incremental to conventional assessment and IS as measured by Ce-MRI.

Left ventricular remodeling can be predicted with left ventricular volume response during dobutamine echocardiography after acute myocardial infarction

OBJECTIVES

This study was performed to evaluate the significance of left ventricular (LV) volume response during dobutamine stress echocardiography (DSE) in the prediction of LV volume change during follow-up (F/U) in patients with acute myocardial infarction (AMI).

METHODS

Forty-five patients with AMI (male 39, age 57+/-10 y, anterior myocardial infarction [MI] 29) underwent DSE 6+/-4 d after AMI. Revascularization of the infarct-related artery was performed if severe stenosis was present. A F/U echocardiography was performed 7.5+/-3.4 mo after DSE. The LV end-diastolic volume (EDV) and end-systolic volume (ESV) using the modified Simpson's method were measured at baseline echocardiography, low-dose (10 microg x kg(-1) x min(-1)) DSE, and F/U echocardiography.

RESULTS

Patients were divided into 2 groups; Group I (n = 21) with an abnormal response (<10% decrease) in LVEDV during low-dose DSE; Group II (n = 24) with a normal response (> or =10% decrease) in LVEDV during low-dose DSE. At F/U echocardiography, the (%) change of LVEDV was significantly different between the 2 groups (-2.0+/-16.7 versus - 22.6+/-24.7%, p<0.01). Using multivariate analysis, the response of LVEDV (%) at low-dose DSE was the only significant independent predictor of the change of LVEDV (%) during F/U (y = 0.85 x - 0.03, r = 0.63, p<0.001).

CONCLUSIONS

The response of LVEDV during DSE can be used as a predictor for the LV volume change after AMI.

Impact of coronary revascularization and transmural extent of scar on regional left ventricular remodelling

AIMS

Transmural extent (TME) of myocardial scar, contractile reserve, and perfusion all predict improvement in regional myocardial function after coronary revascularization. We sought their association with regional remodelling after infarction.

METHODS AND RESULTS

We studied 89 patients (age 62 +/- 10 years) with left ventricular (LV) dysfunction, at least 1 month post infarction. Viability was identified by TME < 75% on contrast-enhanced magnetic resonance imaging (ce-MRI), augmentation at low-dose dobutamine echocardiography (DbE), or >60% uptake on delayed redistribution on TI-201 SPECT (single photon emission computed tomography). Coronary revascularization was performed in 36 patients. Regional LV end-diastolic volume (EDV) and end-systolic volume, and ejection fraction were measured with MRI at baseline and after a median follow-up of 18 months. Of 357 segments identified with subendocardial infarction (TME 0-25%) on ce-MRI, 176 were revascularized. Subendocardial scar segments were associated with reverse regional remodeling during follow-up. Revascularization was an independent correlate of change in EDV, but TME and revascularization showed no interaction with respect to their influence on regional volumes. Contractile reserve was present on DbE in 228 segments, of which 129 were TME 0-25%; remodelling was associated with intervention in non-transmural infarcts showing viability by DbE. Viability was identified by TI-201 SPECT in 381 segments (233 with TME 0-25%), but viability by SPECT was not associated with reverse remodelling. No significant reverse remodelling occurred in segments with intermediate scar thickness (TME 26-75%) or transmural scar, independent of revascularization or viability by DbE or TI-SPECT.

CONCLUSION

Reverse regional remodelling is associated with subendocardial infarction, especially in the setting of contractile reserve and revascularization.

Clinical implications of early mitral regurgitation in patients with reperfused acute myocardial infarction

BACKGROUND

The mechanisms by which mitral regurgitation (MR) may lead to an adverse prognosis after reperfused acute myocardial infarction (AMI) have not been fully investigated. We hypothesized that in the early phase of ST-elevation AMI, MR may lead to progressive left ventricular (LV) remodeling and subsequent heart failure.

METHODS AND RESULTS

A series of 184 patients with AMI successfully treated with primary angioplasty underwent serial two-dimensional echocardiography at admission, at 1 and 6 months, and at 6-month angiography. The mean follow-up was 18 +/- 7 months. On the basis of color Doppler, MR was graded from 0 (none) to 4 (severe). Patients were divided into group 1 (n = 146) with an MR grade of < or = 1 and group 2 (n = 38) with an MR grade of > or = 2. The regurgitant volume and effective regurgitant orifice area of MR were significantly higher in group 2 than in group 1 (36.7 +/- 12.9 mL/beat vs 4.67 +/- 3.2 mL/beat, P < .0001; 22.5 +/- 7.6 mm(2) vs 5.8 +/- 5.7 mm(2), P < .0001, respectively). LV end-diastolic volume progressively increased in group 2 and was significantly higher than in group 1 at 6 months (113.8 +/- 31.8 mL vs 96.9 +/- 34.1 mL, P = .0002), with a higher prevalence of LV remodeling (66% vs 22%, P < .0001). At 2 years, the incidence of heart failure was higher in group 2 than in group 1 (39% vs 12%, P < .0002). A significant correlation was found between effective regurgitant orifice area of MR and baseline to 6-month change of LV end-diastolic volume (P = .001). By stepwise multivariate regression analysis effective regurgitant orifice area of early MR was an independent predictor of LV remodeling (P = .001) and late heart failure (hazard ratio: 1.069, 95% confidence interval 1.033-1.106, P < .0001, Cox analysis).

CONCLUSION

In reperfused AMI, early high-degree MR is an important predictor of both LV dilation and subsequent heart failure.

Prevalence, predictors, time course, and long-term clinical implications of left ventricular functional recovery after mechanical reperfusion for acute myocardial infarction

This study prospectively evaluated the prevalence, predictors, time course, and prognostic impact of left ventricular (LV) functional recovery after successful primary percutaneous coronary intervention in 228 consecutive patients with acute myocardial infarctions (AMIs) and LV dysfunction. Serial echocardiographic exams were performed within 24 hours (time 1) and at 1 month (time 2) and 6 months (time 3) after AMI. Overall, 133 patients (58%) showed significant LV functional recovery (> or =10% ejection fraction increase compared with time 1 or ejection fraction > or =50%) at time 3. Early (from time 1 to time 2) and late (from time 2 to time 3) functional recovery patterns were detected in 102 patients (45%) and 31 patients (14%), respectively. Independent predictors of LV functional recovery were enzymatic infarct size (p = 0.0001), time from symptom onset to reperfusion (p = 0.022), extent and severity of baseline LV wall motion abnormalities (p = 0.007), and female gender (p = 0.031). Six-month LV remodeling rates were 36% and 64% in patients with and without LV functional recovery (p = 0.0001). The five-year cardiac death rate was significantly lower in patients with LV functional recovery than in those without (8% vs 18%, respectively, p = 0.024). The time course of LV functional recovery during 6 months did not significantly affect long-term survival. In conclusion, after successful mechanical reperfusion of AMIs, nearly half of patients showed poor LV functional recovery. The presence of significant LV functional recovery 6 months after reperfused AMI, but not the specific time course of recovery, is clearly associated with a better long-term clinical outcome. Simple baseline variables can predict the improvement of cardiac function after reperfused AMI.