A prospective evaluation of left ventricular remodeling after inaugural anterior myocardial infarction as a function of gene polymorphisms in the renin-angiotensin-aldosterone, adrenergic, and metalloproteinase systems

Investigation of association of genetic variant rs3918242 of matrix metalloproteinase-9 with hypertension, myocardial infarction and progression of ventricular dysfunction in Irish Caucasian patients with diabetes: a report from the STOP-HF follow-up programme

Background

Hypertension and/or myocardial infarction are common causes of heart failure in Type 2 diabetes. Progression to heart failure is usually preceded by ventricular dysfunction, linked to matrix metalloproteinase (MMP) mediated extracellular matrix changes. We hypothesise that the minor allele of genetic variant rs3918242 in the promoter region of the MMP-9 gene is associated with hypertension and/or myocardial infarction, with resultant progression of dysfunctional cardiac remodelling in patients with diabetes without symptomatic heart failure.

Methods

We genotyped 498 diabetes patients participating in the St Vincent’s Screening TO Prevent Heart Failure (STOP-HF) follow-up programme for the rs3918242 single nucleotide polymorphism and investigated associations with the co-primary endpoints hypertension and/or myocardial infarction using a dominant model. We also evaluated resulting cardiometabolic phenotype and progression of ventricular dysfunction and cardiac structural abnormalities over a median follow-up period of 3.5 years.

Results

The CT/TT genotype comprised 28.1% of the cohort and was associated with a twofold higher risk of myocardial infarction (17.9% vs 8.4%), a reduction in ejection fraction and greater left ventricular systolic dysfunction progression [adjusted OR = 2.56 (1.09, 6.01), p = 0.026] over a median follow-up of 3.5 years [IQR 2.6, 4.9 years]. Conversely, rs3918242 was not associated with hypertension, blood pressure, pulse pressure or left ventricular mass index at baseline or over follow up.

Conclusions

Diabetes patients with the minor T allele of rs3918242 in the STOP-HF follow up programme have greater risk of myocardial infarction, lower ejection fraction and greater progression of left ventricular systolic abnormalities, a precursor to heart failure. These data may support further work on MMP-9 as a biomarker of ventricular dysfunction and the investigation of MMP-9 inhibitors for heart failure prevention in diabetes, particularly in the post-infarction setting.

ClinicalTrials.gov Identifier: NCT00921960

Long-term prognostic impact of left ventricular remodeling after a first myocardial infarction in modern clinical practice

Background

The association of left ventricular remodeling (LVR) after myocardial infarction (MI) with the subsequent risk of heart failure (HF) and death has not been studied in patients receiving optimal secondary prevention.

Methods and results

We performed a long-term clinical follow-up of patients included in 2 prospective multicentric studies on LVR after first anterior MI. At 1-year echocardiography, LVR (≥20% increase in end-diastolic volume from baseline to 1 year) occurred in 67/215 (31%) patients in cohort 1 and in 87/226 (38%) patients in cohort 2. The prescription rate of secondary prevention medications was very high (ß-blockers at 1 year: 90% and 95% for cohorts 1 and 2, respectively; angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (ACE-I/ARB) at 1 year: 93% and 97% for cohorts 1 and 2, respectively). Median clinical follow-up after LVR assessment was 11.0 years in cohort 1 and 7.8 years in cohort 2. In both cohorts, LVR patients had a progressive increase in the risk of cardiovascular death or hospitalization for HF (p = 0.0007 in cohort 1 and 0.009 in cohort 2) with unadjusted hazard ratios of 2.52 [1.45–4.36] and 2.52 [1.23–5.17], respectively. Similar results were obtained when cardiovascular death was considered as an isolated endpoint. After adjustement on baseline characteristics including ejection fraction, the association with the composite endpoint was unchanged.

Conclusion

In a context of a modern therapeutic management with a large prescription of evidence-based medications, LVR remains independently associated with HF and cardiovascular death at long-term follow-up after MI.

Left Ventricular Remodelling: A Problem in Search of Solutions

Cardiac remodelling (REM) is a generally unfavourable process that leads to left ventricular dilation in response to cardiac injury, predominantly acute myocardial infarction (AMI). REM occurs in around 30 % of anterior infarcts despite timely primary coronary intervention and the use of drugs, i.e. angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARBs), beta-blockers, aldosterone inhibitors and statins. In order to diagnose REM, many imaging modalities (echocardiography, cardiac magnetic resonance, scintigraphy) are employed together with an increasing number of serum biomarkers including microRNAs. The most widely used definition of REM is a >20 % increase in left ventricular end-diastolic volume (LVEDV). There is also evidence that regression of REM can occur, i.e. reverse REM. The latter is defined as a ≥10 % decrease in left ventricular end-systolic volume (LVESV) and confers a more favourable outcome. Many therapeutic agents may be used during primary intervention and over the long term; however, few have demonstrated significant benefits. Revascularisation, anti-REM surgery and, where indicated, cardiac resynchronisation therapy can be of benefit. Gene therapy by sarcoplasmic reticulum Ca²⁺ ATPase 2 (SERCA-2a) transfer has been investigated but data from the Calcium upregulation by percutaneous administration of gene therapy in patients with cardiac disease (CUPID 2) trial were disappointing. Progenitor cell therapy shows promise. In conclusion, therapy for REM remains inadequate.

Matrix metalloproteinase-2 (MMP-2) gene polymorphism and cardiovascular comorbidity in type 2 diabetes patients

OBJECTIVE

Matrix metalloproteinases (MMPs) play an important role in pathogenesis of atherosclerosis and vascular disease. We hypothesized that MMP-2 might be a susceptibility gene for cardiovascular disease (CVD) in diabetes. The aim of this study was to evaluate the association between C(-1306)T functional polymorphism in the MMP-2 gene and risk of CVD in type 2 diabetes patients.

METHODS

We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the C(-1306)T polymorphism by polymerase chain reaction (PCR) and restriction analysis.

RESULTS

A significant decrease of T allele frequency was observed in patients with CVD versus those with no CVD (OR 0.44, 95% CI 0.36-0.52, p<0.0001). In contrast, OR for CC genotype was 2.19 (1.79-2.68, p<0.0001), conferring 2-fold greater odds for CVD. When the distribution of C(-1306)T was compared in subgroups with different clinical phenotypes of CVD, patients with stroke had the lowest frequency of T allele (6% vs. 11%), compared to entire CVD+ group (p<0.05).

CONCLUSIONS

T2DM patients carrying the T allele of MMP-2 C(-1306)T polymorphism have a significantly reduced risk of CVD. The C(-1306)T polymorphism is associated with susceptibility to stroke in T2DM patients.

Association of polymorphisms of zinc metalloproteinases with clinical response to stem cell therapy

AIM

The purpose of this study was to assess the associations of polymorphisms in two metalloproteinase genes-metalloproteinase-2 (MMP-2) and angiotensin converting enzyme (ACE)-with clinical response to autologous transplantation of mononuclear bone marrow cells (MBMC) in patients with acute myocardial infarction.

METHODS

The double centre study included 48 patients with a first acute myocardial infarction treated with primary coronary angioplasty, stent implantation and transplantation of MBMC. According to the changes in perfusion defect size, left ventricle ejection fraction, end-systolic volume and peak systolic velocity of the infracted wall (dSaMI) after cell therapy, the patients were retrospectively divided into group A (responders) and group B (non-responders). Genomic DNA was isolated from peripheral leukocytes by a standard technique using proteinase K. Three MMP-2 promoter (-1575G/A, -1306C/T and -790T/G) as well as I/D ACE gene polymorphisms were detected by PCR methods with restriction analyses (when necessary) according to standard protocols.

RESULTS

Of the 48 patients who received MBMC transplantation, 17 responded to the therapy. There were no significant differences in the prevalence of matrix metalloproteinase-2 triple genotype GGCCTT between responder/non-responder groups (71% versus 61%, p=0.375). Similarly, no differences in either genotype distribution or allelic frequencies of I/D ACE polymorphism between responders and non-responders to the cell therapy were observed (p=0.933). Compared to patients with ACE genotype ID or DD, the patients with ACE II genotype significantly improved in regional systolic LV function of the infarcted wall after implantations of MBMC (dSaMI - 0.4 versus 1.4 cm/s, p=0.037).

CONCLUSION

In our study, the ACE genotype II was associated with improvement of regional systolic LV function of the infarcted wall after implantations of MBMC. The detected polymorphism in matrix metalloproteinase-2 gene was not associated with clinical response to cell therapy.

Late recovery in left ventricular systolic function after discharge of patients with a first anterior myocardial infarction

BACKGROUND

Left ventricular systolic function is a useful indicator of in-hospital prognosis in patients with acute myocardial infarction. For long-term risk stratification, however, the variable degree of recovery that may occur during the ensuing period has also to be taken into account.

AIMS

To analyse the prevalence, time course, determinants and correlates of late left ventricular function recovery after myocardial infarction, from hospital discharge to 1-year follow-up, using systematic serial assessment of left ventricular function.

METHODS

Data from 512 patients with a first anterior myocardial infarction included in two prospective studies on left ventricular remodelling (REVE and REVE-2) were analysed. Serial echocardiographic studies were performed before discharge, at 3 months and at 1 year after myocardial infarction. Left ventricular volumes, ejection fraction, and Wall Motion Score Index were determined at a core echocardiographic laboratory.

RESULTS

In both cohorts, there was a significant decrease in Wall Motion Score Index between discharge and 1 year (from 1.87 ± 0.15 to 1.71 ± 0.21 [P<0.0001] in REVE; and from 1.91 ± 0.15 to 1.64 ± 0.28 [P<0.0001] in REVE-2), indicating an improvement in systolic function. Left ventricular ejection fraction increased from 49.6 ± 9.5% at baseline to 51.5 ± 9.5% at 1 year in REVE (P<0.008), and from 49.8 ± 8.3% to 55.5 ± 9.8% in REVE-2 (P<0.0001). Most of the recovery occurred within the first 3 months after discharge, but there was still significant recovery between 3 months and 1 year. Peak creatine kinase was the sole variable independently associated with left ventricular function recovery in both studies. Patients with no or minimal function recovery had the greater increase in left ventricular volumes at 1 year.

CONCLUSIONS

Late recovery in left ventricular function is common after discharge in patients with acute myocardial infarction. Further research is needed to identify new parameters that may help to predict this favourable outcome.

Decreased serine207 phosphorylation of troponin T as a biomarker for left ventricular remodelling after myocardial infarction

AIMS

Chronic heart failure following myocardial infarction (MI) is characterized by progressive left ventricular remodelling (LVR). Despite significant improvements in MI management, LVR remains a frequent complication. Although several risk factors have been identified, such as infarct size, LVR is difficult to predict in clinical practice.

METHODS AND RESULTS

Using a rat model of MI and phosphoproteomic technology, we discovered that remodelling is associated with decreased levels of myocardial and plasma serine(208)-phosphorylated troponin T (TnT). To confirm the association in human plasma, we developed new specific polyclonal antibodies against human/rat serine(207/208)-phosphorylated TnT and tested plasma obtained in the first week after MI from patients with low, intermediate, and high remodelling a year later. We observed a significant decrease of serine(207)-phosphorylated TnT and of the serine(207)-phosphorylated TnT/total TnT ratio in those with intermediate or high LVR. These differences remained statistically significant when adjusted for other determinants of LVR. In contrast, baseline B-type natriuretic peptide levels were not associated with LVR.

CONCLUSION

The level of circulating phosphorylated TnT could be a new biomarker of LVR.

Deep plasma proteomic analysis of patients with left ventricular remodeling after a first myocardial infarction

PURPOSE

Depletion of major blood proteins is one of the most promising approaches to accessing low abundance biomarkers for proteomics studies. The use of combinatorial peptide ligand library (CPLL) for accessing these low abundance proteins in plasma from patients with a myocardial infarction (MI) was tested to identify candidate protein biomarkers of left ventricular remodeling (LVR).

EXPERIMENTAL DESIGN

Serial blood samples of MI patients followed for one year (at inclusion, 1 month, 3 months, and 1 year) were treated with CPLL and analyzed by SELDI-TOF-MS.

RESULT

The use of CPLL increased resolution, with loss of most abundant plasma proteins, reproducibly and improved the intensity of low-abundance proteins. Longitudinal information allowed us to reduce by 55% the final number of peaks identified as significantly modulated throughout the 1-year follow-up after MI. Interestingly, 19 of the 26 peaks finally selected were detected only in samples treated from CPLL. The 2777 m/z peak, found in less elevated level in high remodeling patients, was identified as being DAHKSEVAHR FKDLGEENFKALVL, the N-terminal peptide (24-48 aa) generated from albumin by pepsin cleavage.

CONCLUSIONS AND CLINICAL RELEVANCE

This finding shows the potential of CPLL in accessing low-abundance proteins to select and identify candidate biomarkers in patients with LVR.

Evaluation of myocardial relaxation in conditions of cardiac remodeling

The term cardiodynamics refers to dynamic events associated with cardiac contraction and relaxation. The occurring wave of excitement spreads very quickly along the entire atrial musculature and after a brief AV retention it affects all muscle cells of the ventricles. Excitation, that is, the increase in action potentials, precedes the contraction of the myocardium, which follows the 'all or none' rule. Each contraction results in relaxation of the myocardium, so that the contraction and relaxation cycles continually follow each other in succession. The entire cardiodynamics, hemodinamics, i.e. signaling mechanisms of the heart are altered in the remodeling (alternation) condition of the left ventricular myocardium, i.e. the musculature and the whole arterial wall. Remodeling of the cardiac wall and layers of the arterial wall is a negative factor, because it leads to disturbances of the cardiac contraction and relaxation cycles and incites progression of the arterial hypertension, emergence of atherosclerosis and arterial stenosis. Today, the genetic base of the cardiac remodeling is the object of intensive studies. Cardiomyopathies are primary disorders of the myocardium associated with abnormalities of the cardiac wall thickness, the size of chambers, contractions, relaxations, signal conduct and rhythm. They are the major cause of morbidity and mortality for all age groups. Mechanisms of these events on the molecular level will be discussed in the following study.

Predicting left ventricular remodeling after a first myocardial infarction by plasma proteome analysis

Recent improvements in therapeutic strategies did not prevent left ventricular remodeling (LVR), which remains a common event (30%) after acute myocardial infarction (AMI). We report the use of a systematic approach, based on comparative proteomics, to select circulating biomarkers that may be associated with LVR. We selected 93 patients enrolled in a prospective study. These patients with anterior wall Q-wave AMI underwent echocardiographic follow-up at hospitalization, 3 months and 1 year after AMI. They were divided into three groups (no, low, or high remodeling). Plasma samples of these patients (day 5 of hospitalization) were processed and stored at -80 degrees C within 2 h and analyzed using SELDI-TOF protein chip technology. This systematic approach allowed to select candidate proteins modulated by LVR: post-translational variants of alpha1-chain of haptoglobin (Hpalpha1) corresponding to m/z 9493, 9565, and 9623, which were more elevated in remodeling patients. The peak 9493 m/z was shown having a receiving-operating characteristic (ROC) value of 0.71 between non- and remodeling patients. SELDI-TOF approach may lead to the identification of circulating proteins associated with LVR. Whether these candidate proteins will help to identify patients who are at high risk of heart failure after AMI will have to be tested in future studies.

Left ventricular remodeling is associated with the severity of mitral regurgitation after inaugural anterior myocardial infarction--optimal timing for echocardiographic imaging

BACKGROUND

Although mitral regurgitation (MR) has been associated with an increased risk of death and heart failure after myocardial infarction (MI), the relationship between post-MI MR and left ventricular (LV) remodeling has not been entirely clarified. In addition, the optimal timing for assessing MR after MI remains unknown.

METHODS

Post-MI MR was assessed by Doppler echocardiography at hospital discharge (baseline) and after 3 months in 261 patients with an inaugural anterior MI. We studied LV remodeling during a 1-year period and clinical follow-up after 3 years, according to MR severity at baseline and at 3 months.

RESULTS

Left ventricular remodeling was demonstrated as an increase in LV end-diastolic volume from 56 +/- 15 mL/m(2) at baseline to 63 +/- 19 mL/m(2) at 1 year (P < .0001). MR severity at baseline was not significantly associated with LV remodeling. By contrast, MR severity at 3 months was a strong indicator of LV remodeling. There was a graded increase in the proportion of patients with a >20% increase in LV end-diastolic volume between baseline and 1 year according to MR severity at 3 months (no MR: 21%, mild MR: 32%, moderate/severe MR: 60%) (P = .008). Both MR at baseline and at 3 months were associated with death or rehospitalization for heart failure by univariate analysis (P = .014 and P < .0001, respectively). By multivariable analysis, MR at baseline was not an independent predictor of adverse outcome (P = .66). By contrast, MR at 3 months was independently associated with adverse outcome with a hazard ratio of 2.23 (1.02-4.91 [P = .04]).

CONCLUSIONS

After an inaugural anterior MI, MR is associated with LV remodeling and adverse clinical outcome. For prognostic purpose, the optimal timing for assessing MR is the chronic post-MI stage rather than the early post-MI period.