Dobutamine stress MRI in pulmonary hypertension: relationships between stress pulmonary artery relative area change, RV performance, and 10-year survival.

In pulmonary hypertension (PH), right ventricular (RV) performance determines survival. Pulmonary artery (PA) stiffening is an important biomechanical event in PH and also predicts survival based on the PA relative area change (RAC) measured at rest using magnetic resonance imaging (MRI). In this exploratory study, we sought to generate novel hypotheses regarding the influence of stress RAC on PH prognosis and the interaction between PA stiffening, RV performance and survival. Fifteen PH patients underwent dobutamine stress-MRI (ds-MRI) and right heart catheterization. RACREST, RACSTRESS, and ΔRAC (RAC STRESS - RAC REST) were correlated against resting invasive hemodynamics and ds-MRI data regarding RV performance and RV-PA coupling efficiency (n'vv [RV stroke volume/RV end-systolic volume]). The impact of RAC, RV data, and n'vv on ten-year survival were determined using Kaplan-Meier analysis. PH patients with a low ΔRAC (<-2.6%) had a worse long-term survival (log-rank P = 0.045, HR for death = 4.46 [95% CI = 1.08-24.5]) than those with ΔRAC ≥ -2.6%. Given the small sample, these data should be interpreted with caution; however, low ΔRAC was associated with an increase in stress diastolic PA area indicating proximal PA stiffening. Associations of borderline significance were observed between low RACSTRESS and low n'vvSTRESS, Δη'VV, and ΔRVEF. Further studies are required to validate the potential prognostic impact of ΔRAC and the biomechanics potentially connecting low ΔRAC to shorter survival. Such studies may facilitate development of novel PH therapies targeted to the proximal PA.

Galectin-3 and cardiac function in survivors of acute myocardial infarction.

BACKGROUND: Galectin-3 is a biomarker associated with inflammation and fibrosis that predicts adverse outcome and relates to biomarkers of extracellular matrix turnover in patients with heart failure, particularly when left ventricular (LV) systolic function is preserved. Whether galectin-3 is related to LV remodeling after acute myocardial infarction is unknown. METHODS AND RESULTS: Circulating galectin-3 and various extracellular matrix biomarkers were measured in 100 patients (age, 58.9±12.0 years; 77% men) admitted with acute myocardial infarction and LV dysfunction, at baseline (mean 46 hours) and at 24 weeks, with cardiac MRI at each time-point. LV remodeling was defined as change in LV end-systolic volume index. Relationships among galectin-3, biomarkers, and LV remodeling were analyzed across the entire cohort, then according to median baseline LV ejection fraction. Galectin-3 levels were elevated in 22 patients (22%) at baseline and increased significantly over time from 14.7±5.5 to 16.3±6.6 ng/mL (P=0.007). Baseline galectin-3 did not correlate with any LV parameters at baseline or change in any parameter over time. Galectin-3 was positively associated with remodeling in patients with supramedian baseline LV ejection fraction (ie, >49.2%; r=0.40; P=0.01) but not when LV ejection fraction was ≤49.2%. Galectin-3 correlated significantly with matrix metalloproteinase-3 and monocyte chemoattractant protein-1 at baseline, biomarkers that have been shown to relate to LV remodeling in this cohort. CONCLUSIONS: Galectin-3 correlated significantly with certain biomarkers involved in extracellular matrix turnover, although no definite relationship was identified with LV remodeling. Whether galectin-3 plays a pathological role in remodeling remains unclear but merits further study. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00132093.

Interleukin-21--a biomarker of importance in predicting myocardial function following acute infarction?

INTRODUCTION: Following acute myocardial infarction (AMI), the acute inflammatory response contributes to wound healing but also to progressive myocardial injury. Interleukin-21 (IL-21) plays a key role in immunoregulation; whether IL-21 is associated with left ventricular (LV) remodelling after AMI is unknown. METHODS: Plasma IL-21 concentrations were measured in 100 patients (age 58.9 ± 12.0 years, 77% male) admitted with AMI and LV dysfunction, at baseline (mean 46 h) and again at 24 weeks; cardiac magnetic resonance and measurement of B-type natriuretic peptide, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-2, -3, -9, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -4 occurred at both time-points. Remodelling was defined as change in LV end-systolic volume index (ΔLVESVI). RESULTS: Plasma IL-21 concentration was unchanged over time (48.1 [SD 35.4]pg/mL at baseline vs. 48.8 [61.3]pg/mL at 24 weeks, p=0.92). Baseline IL-21 correlated significantly with ΔLVESVI (r=0.30, p=0.005) and change in LV end-diastolic volume index (r=0.33, p=0.003). On multivariate analysis, plasma IL-21 was an independent predictor of remodelling. IL-21 was also significantly associated with higher TIMP-4 concentrations and lower MMP-9 concentrations at baseline. CONCLUSIONS: IL-21 predicts adverse remodelling following AMI in patients with LV dysfunction. Whether it plays a direct pathophysiological role in remodelling merits further study.

Altered relative concentrations of high-energy phosphates in patients with uraemic cardiomyopathy measured by magnetic resonance spectroscopy.

BACKGROUND: Premature sudden cardiovascular death is the commonest cause of death in end-stage renal disease (ESRD) patients and is associated with uraemic cardiomyopathy [left ventricular hypertrophy (LVH), systolic dysfunction (LVSD) or LV dilation]. High-energy phosphates (HEP), quantified using phosphorus-31 magnetic resonance spectroscopy, are reduced in patients with diabetes, heart failure and uraemia. Phosphocreatine:ß adenosine triphosphate (PCr:ATP) ratio is an index of metabolic activity. We compared resting HEPs in ESRD patients and hypertensive patients (with and without LVH) who had normal renal function (LVH-only or normal myocardia). We also assessed associations of HEP levels with abnormalities of uraemic cardiomyopathy. METHODS: Fifty-three ESRD and 30 hypertensive patients (18 with LVH, 12 with normal myocardia) underwent phosphorus magnetic resonance spectroscopy of their left ventricle. PCr:ATP ratios were calculated from (31)P-MR spectra obtained from long-axis views of the left ventricle. RESULTS: There were no significant differences in age, LV mass, chamber sizes and ejection fraction between patient groups. PCr:ATP was significantly lower in ESRD patients compared to hypertensive patients, irrespective of the presence or absence of LVH (P = 0.01). In the ESRD group, PCr:ATP was significantly lower in patients with LVSD (P = 0.05) and LV dilation (P = 0.01). LVH was not associated with significant difference in PCr:ATP. CONCLUSIONS: ESRD patients have lower HEP levels compared to hypertensive patients. Lower PCr:ATP ratio, indicating altered myocardial metabolic function in ESRD patients, is associated with features of uraemic cardiomyopathy.

Aldosterone and cortisol predict medium-term left ventricular remodelling following myocardial infarction.

AIMS: Mineralocorticoid receptor (MR) antagonists improve cardiovascular outcomes in patients with heart failure complicating acute myocardial infarction (AMI) and in chronic heart failure. It is unclear whether these beneficial effects are due solely to aldosterone blockade, as MR has a similar affinity for cortisol. We examined the relationships between plasma and urinary steroid hormones and left ventricular (LV) remodelling in patients with LV dysfunction following AMI. METHODS AND RESULTS: Plasma concentrations of renin, aldosterone, and N-terminal pro-brain natriuretic peptide (NT-proBNP), and 24 h urinary excretion rates of tetrahydroaldosterone (THAldo) and total cortisol metabolites were measured in 93 patients at a mean of 46 h following AMI prior to contrast-enhanced cardiac magnetic resonance (ceCMR). Patients were then randomized to 24 weeks of placebo or eplerenone therapy in addition to standard treatment, after which ceCMR was repeated. In placebo-treated patients, aldosterone, NT-proBNP, and excretion rates of THAldo and total cortisol metabolites were univariate predictors of remodelling (i.e. change in LV end-systolic volume index); aldosterone (P = 0.040) and total cortisol metabolite excretion (P = 0.038) remained independent predictors on multivariate analysis. None of the measured biomarkers predicted remodelling in the presence of eplerenone. Plasma and urinary aldosterone measures, and urinary cortisol metabolites, were not only related to larger infarct volumes and greater infarct remodelling over time, but were also higher in patients with microvascular obstruction on baseline ceCMR. CONCLUSION: Aldosterone and cortisol are associated with medium-term LV remodelling when measured early after AMI. The beneficial effects of MR antagonism may relate to blockade of both aldosterone- and cortisol-induced MR activation.

Plasma TIMP-4 predicts left ventricular remodeling after acute myocardial infarction.

BACKGROUND: Alterations in the balance between matrix metalloproteinases and their endogenous tissue inhibitors (TIMPs) are associated with left ventricular (LV) remodeling after acute myocardial infarction (AMI). No relationships have been identified between TIMPs and serial postinfarction change in LV function. METHODS AND RESULTS: Plasma concentrations of TIMP-1, -2, -4 were measured at baseline (mean 46 h) and at 24 weeks in 100 patients (age 58.9 ± 12 years, 77% male) admitted with AMI and LV dysfunction, with cardiac magnetic resonance imaging at each time point. TIMP-1 concentration was reduced, whereas TIMP-2 and -4 concentrations were elevated at baseline compared with a reference control population. TIMP-1 decreased and TIMP-2 increased significantly over time; there was an incremental trend in TIMP-4 concentration. Baseline TIMP-4 correlated with change in LV end-systolic volume index (∆LVESVI; r = 0.24; P = .023) and change in LV end-diastolic volume index (∆LVEDVI; r = 0.25; P = .015). ∆TIMP-4 also correlated with ∆LVESVI and with ∆LVEDVI, as did ∆TIMP-2. On multivariable analysis, baseline TIMP-4 concentration was an independent predictor of ∆LVESVI. CONCLUSIONS: Plasma TIMP-4 concentration, measured early after AMI, may assist in the prediction of LV remodeling and therefore in the assessment of prognosis. Further study of the role of the TIMPs in the pathophysiology of postinfarction remodeling is warranted.

Radiofrequency ablation for persistent atrial fibrillation in patients with advanced heart failure and severe left ventricular systolic dysfunction: a randomised controlled trial.

OBJECTIVE: To determine whether or not radiofrequency ablation (RFA) for persistent atrial fibrillation in patients with advanced heart failure leads to improvements in cardiac function. SETTING: Patients were recruited from heart failure outpatient clinics in Scotland. DESIGN AND INTERVENTION: Patients with advanced heart failure and severe left ventricular dysfunction were randomised to RFA (rhythm control) or continued medical treatment (rate control). Patients were followed up for a minimum of 6 months. MAIN OUTCOME MEASURE: Change in left ventricular ejection fraction (LVEF) measured by cardiovascular MRI. RESULTS: 22 patients were randomised to RFA and 19 to medical treatment. In the RFA group, 50% of patients were in sinus rhythm at the end of the study (compared with none in the medical treatment group). The increase in cardiovascular magnetic resonance (CMR) LVEF in the RFA group was 4.5±11.1% compared with 2.8±6.7% in the medical treatment group (p=0.6). The RFA group had a greater increase in radionuclide LVEF (a prespecified secondary end point) than patients in the medical treatment group (+8.2±12.0% vs +1.4±5.9%; p=0.032). RFA did not improve N-terminal pro-B-type natriuretic peptide, 6 min walk distance or quality of life. The rate of serious complications related to RFA was 15%. CONCLUSIONS: RFA resulted in long-term restoration of sinus rhythm in only 50% of patients. RFA did not improve CMR LVEF compared with a strategy of rate control. RFA did improve radionuclide LVEF but did not improve other secondary outcomes and was associated with a significant rate of serious complications.

Association between proteinuria and left ventricular mass index: a cardiac MRI study in patients with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality. We hypothesized that the level of proteinuria would correlate with left ventricular mass, providing a potential link between elevated protein excretion, left ventricular hypertrophy (LVH) and the increased mortality seen in patients with CKD. In order to do this, we assessed the determinants of left ventricular mass, measured using cardiac magnetic resonance (CMR) imaging, in patients with CKD. METHODS: Patients attending the renal clinic with CKD stages 2-4 and diabetic nephropathy (n = 26) and IgA nephropathy (n = 23) were recruited. They underwent detailed demographic, biochemical and vascular phenotyping and CMR imaging. Proteinuria was measured using spot protein:creatinine ratio (PCR). Left ventricular mass index (LVMI) was calculated from short-axis cine imaging using Argus software and adjusted for body surface area. RESULTS: Log-PCR correlated significantly with LVMI, as did waist circumference, pulse pressure and systolic blood pressure. LVMI was higher in men. When these variables were entered into a linear regression model, log-PCR (P = 0.006) and systolic blood pressure (P < 0.001) independently predicted LVMI. Renal function was not associated with LVMI. CONCLUSIONS: Using volume-independent CMR imaging, we have demonstrated that the level of urinary protein excretion is independently and significantly associated with left ventricular mass in patients with CKD. This relationship was independent of blood pressure. This finding provides a novel link between CKD and increased cardiovascular risk.

Microvolt T-wave alternans in end-stage renal disease patients--associations with uremic cardiomyopathy.

BACKGROUND AND OBJECTIVES: Premature cardiovascular (CV) events, especially sudden cardiac death, are common in ESRD patients and associated with uremic cardiomyopathy. Identification of high-risk patients is difficult. Microvolt T-wave alternans (MTWA) is a noninvasive method of detecting variability in electrocardiogram (ECG) T-wave morphology and is a promising technique for identifying patients at high risk of ventricular tachyarrhythmias. MTWA results of ESRD and hypertensive left ventricular hypertrophy (LVH) patients were assessed to determine the prevalence of abnormal results and associations with uremic cardiomyopathy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this single-center observational study, 200 ESRD and 30 LVH patients underwent assessment including CV history, ECG, cardiac magnetic resonance imaging, and an MTWA exercise test. MTWA results were classified as "negative" or "abnormal" on the basis of previously published reports. RESULTS: An abnormal MTWA result was more common in ESRD compared with LVH patients (57.5% versus 26.7%, respectively; P = 0.002). In ESRD patients, MTWA was significantly associated with uremic cardiomyopathy, clinical history of atherosclerosis (coronary, cerebral, peripheral) and diabetes mellitus, older age, and hemodialysis therapy. Independent associations with an abnormal MTWA result were older age, macrovascular disease, increased left ventricle (LV) mass, and LV dilation. CONCLUSIONS: Features of uremic cardiomyopathy are associated with an abnormal MTWA result.

The index of microcirculatory resistance measured acutely predicts the extent and severity of myocardial infarction in patients with ST-segment elevation myocardial infarction.

OBJECTIVES: This study investigated the relationship between the index of microcirculatory resistance (IMR) with myocardial injury and microvascular obstruction (MVO) assessed by contrast-enhanced cardiac magnetic resonance (ceCMR) imaging in a broad range of ST-segment elevation myocardial infarction (STEMI) patients undergoing emergency percutaneous coronary intervention (PCI). BACKGROUND: Contrast-enhanced cardiac magnetic resonance imaging is the gold standard for assessment of microvascular obstruction (MVO), left ventricular (LV) ejection fraction, and infarct volumes in ST-segment elevation myocardial infarction (STEMI). However, ceCMR is not available acutely. The index of microcirculatory resistance is a simple invasive measure of microvascular function available at the time of emergency PCI. We investigated the relationship between IMR with myocardial injury and MVO assessed by ceCMR in STEMI patients undergoing emergency PCI. METHODS: Fifty-seven patients with STEMI were included and 53 (93%) and 47 (82%) patients had complete ceCMR scans 2 days and 3 months following MI, respectively. Microvascular obstruction was defined as a dark core of hypoenhancement within the area of hyperenhanced infarct tissue 10 to 15 min following intravenous gadolinium (0.1 mmol/kg). RESULTS: The median IMR (interquartile range [IQR]) was 35 (24 to 63) U. Twenty-seven patients (46%) had MVO. We found that IMR (median [IQR]) was higher in patients with MVO (38 [29 to 55] U) than in patients without MVO (27 [18 to 36] U); p = 0.003). The index of microcirculatory resistance was a negative multivariable predictor of LV ejection fraction, (p < or = 0.001) and infarct volume (p = 0.01) on the ceCMR scan 2 days after MI, and IMR was a multivariable predictor of LV ejection fraction (p = 0.028) and infarct volume (p = 0.048) at 3 months. CONCLUSIONS: The index of microcirculatory resistance measured acutely was higher in patients with MVO on ceCMR, and IMR independently predicted LV function and infarct volume. This easily measured physiological parameter provides important prognostic information at the time of emergency PCI.

Monocyte chemoattractant protein-1: a dichotomous role in cardiac remodeling following acute myocardial infarction in man?

INTRODUCTION: Monocyte chemoattractant protein-1 (MCP-1) is elevated after acute myocardial infarction (AMI), and potentiates left ventricular (LV) remodeling in murine models of AMI. We examined the relationships between serum MCP-1, change in LV function and biomarkers related to remodeling in a cohort of AMI patients. METHODS: Serum MCP-1 concentrations were measured in 100 patients (age 58.9+/-12.0 years, 77% male) admitted with AMI and LV dysfunction, at baseline (mean 46 h), 12 and 24 weeks; cardiac magnetic resonance imaging and measurement of matrix metalloproteinase-2 (MMP-2), MMP-3 and MMP-9 occurred at each time-point. RESULTS: MCP-1 increased significantly from 697 [483, 997]pg/mL at baseline to 878 [678, 1130]pg/mL at 24 weeks (p<0.001). MMP-3 concentration increased while MMP-9 decreased significantly over time; MMP-2 concentration did not change significantly. BASELINE MCP-1 correlated with change in (Delta) LV end-systolic volume index (DeltaLVESVI; r= -0.48, p=0.01) and with DeltaLV ejection fraction (DeltaLVEF; r=0.50, p=0.02). However, DeltaMCP-1 correlated positively with DeltaLVESVI (r=0.40, p=0.006) and negatively with DeltaLVEF (r= -0.36, p=0.004). MCP-1 had no relationship with any MMP. CONCLUSIONS: MCP-1 may have a dichotomous role following AMI, aiding early infarct healing but potentiating later remodeling, which merits further study before any therapeutic trials of MCP-1 modulation in humans.

Microvascular obstruction remains a portent of adverse remodeling in optimally treated patients with left ventricular systolic dysfunction after acute myocardial infarction.

BACKGROUND: Microvascular obstruction (MO) is associated with large acute myocardial infarction and lower left ventricular (LV) ejection fraction and predicts greater remodeling, but whether this effect is abolished by contemporary antiremodeling therapies is subject to debate. We examined the influence of several infarct characteristics, including MO, on LV remodeling in an optimally treated post-acute myocardial infarction cohort, using contrast-enhanced cardiac magnetic resonance. METHODS AND RESULTS: One hundred patients (mean age, 58.9+/-12 years, 77%men) underwent contrast-enhanced cardiac magnetic resonance at baseline (approximately 4 days) and at 12 and 24 weeks. The effects on LV remodeling (ie, change in LV end-systolic volume index [DeltaLVESVi]) of infarct site, transmurality, endocardial extent, and the presence of early and late MO were analyzed. Mean baseline infarct volume index decreased from 34.0 (21.2) mL/m(2) to 20.9 (12.9) mL/m(2) at 24 weeks (P<0.001). Infarct site had no influence on remodeling, but greater baseline infarct transmurality (r=0.47, P<0.001) and endocardial extent (r=0.26, P<0.01) were associated with higher DeltaLVESVi. Early MO was seen in 69 patients (69%) and persisted as late MO in 56 patients (56%). Patients with late MO underwent significantly greater remodeling than those without MO (DeltaLVESVi, +4.1 [13.4] versus -7.0 [12.7] mL/m(2), respectively, P=0.001); those with early MO only displayed an intermediate DeltaLVESVi (-4.9 [13.0] mL/m(2)). Importantly, late MO was seen frequently despite optimal coronary blood flow having been restored at angiography. CONCLUSIONS: Late MO on predischarge contrast-enhanced cardiac magnetic resonance remains an ominous predictor of adverse LV remodeling despite powerful antiremodeling therapy and may be useful in the risk stratification of survivors of acute myocardial infarction.

Association of left atrial volume with mortality among ESRD patients with left ventricular hypertrophy referred for kidney transplantation.

BACKGROUND: Left ventricular hypertrophy (LVH) is common in patients with end-stage renal disease (ESRD) and an independent risk factor for premature cardiovascular death. Left atrial volume (LAV), measured using echocardiography, predicts death in patients with ESRD. Cardiovascular magnetic resonance (CMR) imaging is a volume-independent method of accurately assessing cardiac structure and function in patients with ESRD. STUDY DESIGN: Single-center prospective observational study to assess the determinants of all-cause mortality, particularly LAV, in a cohort of ESRD patients with LVH, defined using CMR imaging. SETTING & PARTICIPANTS: 201 consecutive ESRD patients with LVH (72.1% men; mean age, 51.6 +/- 11.7 years) who had undergone pretransplant cardiovascular assessment were identified using CMR imaging between 2002-2008. LVH was defined as left ventricular mass index >84.1 g/m(2) (men) or >74.6 g/m(2) (women) based on published normal left ventricle dimensions for CMR imaging. Maximal LAV was calculated using the biplane area-length method at the end of left ventricle systole and corrected for body surface area. PREDICTORS: CMR abnormalities, including LAV. OUTCOME: All-cause mortality. RESULTS: 54 patients died (11 after transplant) during a median follow-up of 3.62 years. Median LAV was 30.4 mL/m(2) (interquartile range, 26.2-58.1). Patients were grouped into high (median or higher) or low (less than median) LAV. There were no significant differences in heart rate and mitral valve Doppler early to late atrial peak velocity ratio. Increased LAV was associated with higher mortality. Kaplan-Meier survival analysis showed poorer survival in patients with higher LAV (log rank P = 0.01). High LAV and left ventricular systolic dysfunction conferred similar risk and were independent predictors of death using multivariate analysis. LIMITATIONS: Only patients undergoing pretransplant cardiac assessment are included. Limited assessment of left ventricular diastolic function. CONCLUSIONS: Higher LAV and left ventricular systolic dysfunction are independent predictors of death in ESRD patients with LVH.

Comparison of serial measurements of infarct size and left ventricular ejection fraction by contrast-enhanced cardiac magnetic resonance imaging and electrocardiographic QRS scoring in reperfused anterior ST-elevation myocardial infarction.

BACKGROUND: Left ventricular ejection fraction (LVEF) is a powerful prognostic marker after acute myocardial infarction and is dependent on infarct magnitude. Contrast-enhanced cardiac magnetic resonance (ceCMR) represents the current criterion standard means of LVEF and infarct size measurement. Infarct size and LVEF can be estimated from the 12-lead electrocardiogram (ECG) using the Selvester QRS score. We examined for the first time the relationship between serial measures of LVEF and infarct size by ceCMR and ECG in patients with reperfused anterior ST-elevation myocardial infarction (STEMI) and depressed LVEF. METHODS: Thirty-four patients (mean +/- SD age, 59 +/- 11.8 years; 70.6% male) underwent ceCMR and simultaneous ECG at mean 93 hours after admission and at 12 and 24 weeks. The QRS score was calculated on each ECG, from which infarct size and LVEF were estimated and compared with the equivalent ceCMR measurements. RESULTS: Infarct size on ceCMR was higher than that by QRS score at each time-point (P < .001) with modest correlation (r = 0.56-0.78, P < .001). Left ventricular ejection fraction was consistently significantly higher on CMR than on ECG, with weak correlation (r = 0.37-0.51, P < .05). We derived a novel equation relating QRS score to CMR-measured LVEF in the subacute phase of infarction: LVEF = 61 - (1.7 x QRS score) (%). CONCLUSIONS: In patients with reperfused anterior ST-elevation myocardial infarction and depressed LVEF, ceCMR is moderately correlated with the QRS in the serial measurement of infarct size and LVEF. Infarct size (measured by ceCMR) and LVEF are consistently higher than those calculated on the QRS score in the acute and subacute phases of infarction.

Serum soluble ST2: a potential novel mediator in left ventricular and infarct remodeling after acute myocardial infarction.

OBJECTIVES: This study sought to assess, for the first time, the relationship between serum concentrations of the soluble interleukin-1 receptor family member ST2 (sST2) and serial change in left ventricular (LV) function after acute myocardial infarction (AMI). BACKGROUND: Serum sST2 levels are elevated early after AMI and are associated with lower pre-discharge LV ejection fraction and adverse cardiovascular outcomes. METHODS: The sST2 levels were measured in 100 patients (mean age 58.9 +/- 12.0 years; 77% male), admitted with AMI with resultant LV systolic dysfunction, at baseline and at 12 and 24 weeks. Patients underwent cardiac magnetic resonance imaging and measurement of N-terminal pro-brain natriuretic peptide, norepinephrine, and aldosterone at each time point. RESULTS: Median sST2 decreased from 263.3 pg/ml at baseline to 140.0 pg/ml at 24 weeks (p < 0.001). Serum sST2 correlated significantly with LV ejection fraction at baseline (r = -0.30, p = 0.002) and 24 weeks (r = -0.23, p = 0.026); change in sST2 correlated with change in LV end-diastolic volume index (r = -0.24, p = 0.023). Level of sST2 was positively associated with infarct volume index at baseline (r = 0.26, p = 0.005) and 24 weeks (r = 0.22, p = 0.037), and with change in infarct volume index (r = -0.28, p = 0.001). Level of sST2 was significantly higher in patients with greater infarct transmurality and endocardial extent, and in the presence of microvascular obstruction. Level of sST2 correlated significantly with norepinephrine and aldosterone, but not with N-terminal pro-brain natriuretic peptide. CONCLUSIONS: Measurement of sST2 early after AMI assists in the prediction of medium-term LV functional recovery. Novel relationships were observed between sST2, infarct magnitude/evolution, and aldosterone. Serum sST2 may be of pathophysiological importance in ventricular and infarct remodeling after AMI. (Effects of Eplerenone on Left Ventricular Remodelling Following Heart Attack; NCT00132093).

Tissue plasminogen activator antigen predicts medium-term left ventricular end-systolic volume after acute myocardial infarction.

Von Willebrand factor (VWF) and tissue plasminogen activator (t-PA) predict adverse cardiovascular outcome following acute myocardial infarction (AMI) and are weakly associated with pre-discharge left ventricular ejection fraction (LVEF). We examined the relationships between VWF, t-PA antigen, matrix metalloproteinase (MMP)-2,-3, and -9, and B-type natriuretic peptide (BNP), and their predictive effect on serial change in LV volumes in a cohort of patients admitted with AMI. Plasma VWF, t-PA antigen, MMP-2,-3,-9, and BNP were measured at a mean 46 h after AMI in 100 patients (mean age 58.9 +/- 12 years, 77% male) with depressed LVEF. Cardiac magnetic resonance (CMR) imaging was then performed. Biomarker measurement and CMR were repeated at 12 and 24 weeks. Plasma concentrations of VWF, BNP and MMP-9 were elevated while t-PA antigen concentration was at the upper limits of normal; over 24 weeks VWF, t-PA antigen, MMP-9 and BNP decreased significantly. Baseline VWF correlated with BNP (r = 0.35, P < 0.001) and MMP-3 (r = 0.24, P = 0.019) as did t-PA antigen (r = 0.27, P = 0.007 for BNP; r = 0.40, P < 0.001 for MMP-3). t-PA antigen, VWF, MMP-3 and BNP were univariate predictors of LV end-systolic volume at 24 weeks; tPA antigen and BNP remained significant independent predictors on multivariate analysis. t-PA antigen and VWF are related to medium-term LV volumes after AMI, and to MMP-3. This novel link between the coagulation-fibrinolysis system and matrix turnover merits further study in understanding the pathophysiology of adverse ventricular remodeling after AMI.

Validation of magnetic resonance myocardial perfusion imaging with fractional flow reserve for the detection of significant coronary heart disease.

BACKGROUND: Magnetic resonance myocardial perfusion imaging (MRMPI) has a number of advantages over the other noninvasive tests used to detect reversible myocardial ischemia. The majority of previous studies have generally used quantitative coronary angiography as the gold standard to assess the accuracy of MRMPI; however, only an approximate relationship exists between stenosis severity and functional significance. Pressure wire-derived fractional flow reserve (FFR) values <0.75 correlate closely with objective evidence of reversible ischemia. Accordingly, we have compared MRMPI with FFR. METHODS AND RESULTS: One hundred three patients referred for investigation of suspected angina underwent MRMPI with a 1.5-T scanner. The stress agent was intravenous adenosine (140 microg . kg(-1) . min(-1)), and the first-pass bolus contained 0.1 mmol/kg gadolinium. In the following week, coronary angiography with pressure wire studies was performed. FFR was recorded in all patent major epicardial coronary arteries, with a value <0.75 denoting significant stenosis. MRMPI scans, analyzed by 2 blinded observers, identified perfusion defects in 121 of 300 coronary artery segments (40%), of which 110 had an FFR <0.75. We also found that 168 of 179 normally perfused segments had an FFR > or = 0.75. The sensitivity and specificity of MRMPI for the detection of functionally significant coronary heart disease were 91% and 94%, respectively, with positive and negative predictive values of 91% and 94%. CONCLUSIONS: MRMPI can detect functionally significant coronary heart disease with excellent sensitivity, specificity, and positive and negative predictive values compared with FFR.

Left ventricular remodeling after acute myocardial infarction: does eplerenone have an effect?

AIMS: Aldosterone antagonism reduces cardiovascular morbidity and mortality in patients with left ventricular (LV) systolic dysfunction and heart failure or diabetes after acute myocardial infarction (AMI). The mechanism of this effect is unclear. We performed a contrast-enhanced cardiac magnetic resonance study to assess the effects of eplerenone on LV remodeling after AMI. METHODS: One hundred patients (mean age, 58.9 +/- 12 years; 77% male) with LV systolic dysfunction but without heart failure or diabetes were randomized to 24 weeks' double-blind treatment with eplerenone or placebo started 1 to 14 days after AMI. Contrast-enhanced cardiac magnetic resonance was performed, and plasma concentrations of matrix metalloproteinase-2 (MMP-2) and MMP-9 were measured before randomization and at 12 and 24 weeks. RESULTS: Baseline LV ejection fraction was, by chance, significantly higher in eplerenone than in placebo-treated patients. Eplerenone had no effect on the primary end point (change in LV end-systolic volume index); after covariate adjustment, the primary end point fell by 6.1 +/- 2.7 mL/m2 with eplerenone compared to placebo (P = .027), and LV end-diastolic volume index fell by 7.5 +/- 3.4 mL/m2 (P = .031); eplerenone did not significantly influence LV ejection fraction. Eplerenone, after covariate adjustment, significantly decreased MMP-2 and increased MMP-9 over 24 weeks relative to placebo. CONCLUSIONS: In a population of patients with AMI with high uptake of contemporary antiremodeling therapy, eplerenone provides modest incremental protection against LV remodeling, only after covariate adjustment.