Plasma metalloproteinase-9 and restrictive filling pattern as major predictors of outcome in patients with ischemic cardiomyopathy

Novel Biomarkers in Cardiac Resynchronization Therapy: Hepatocyte Growth Factor Is an Independent Predictor of Clinical Outcome

INTRODUCTION AND OBJECTIVES

Cardiac resynchronization therapy (CRT) is beneficial for selected heart failure (HF) patients, although nonresponse to therapy is still prevalent. We investigated a set of novel biomarkers associated with various pathophysiological pathways of HF. Our purpose was to assess their ability to predict clinical outcomes after CRT.

METHODS

We studied 136 chronic HF patients undergoing CRT. We measured the plasma levels of fractalkine, pentraxin-3, hepatocyte growth factor (HGF), carbohydrate antigen-125, and matrix metalloproteinase-9 before and 6 months after CRT. The primary endpoint of the study was 5-year all-cause mortality, and we considered the absence of 6-month reverse remodelling (defined as at least a 15% decrease in end-systolic volume) as a secondary endpoint.

RESULTS

Fifty-eight patients died during the 5-year follow-up period and 66 patients were categorized as nonresponders. In multivariable models, only an increased HGF was an independent predictor of both mortality (HR, 1.35; 95%CI, 1.11-1.64; P=.003; per 1 standard deviation increase) and the absence of reverse remodelling (OR, 1.83; 95%CI, 1.10-3.04; P=.01; per 1 standard deviation increase). Applying HGF to the basic multivariable model of both mortality (net reclassification improvement=0.69; 95%CI, 0.39-0.99; P<.0001; integrated discrimination improvement=0.06; 95%CI, 0.02-0.11) and reverse remodelling (net reclassification improvement=0.39; 95%CI, 0.07-0.71; P=.01; integrated discrimination improvement=0.03; 95%CI, 0.00-0.06) resulted in a statistically significant reclassification and discrimination improvement.

CONCLUSIONS

Of the investigated biomarkers, only HGF predicted clinical outcomes following CRT independently of other parameters. Reclassification analyses showed that HGF measurements could be useful in refining patient selection.

Abnormal diastolic function underlies the different beneficial effects of cardiac resynchronization therapy on ischemic and non-ischemic cardiomyopathy

OBJECTIVES:

To investigate the association between diastolic function and the different beneficial effects of cardiac resynchronization therapy in patients with heart failure due to different causes.

METHODS:

The 104 enrolled patients were divided into an ischemic cardiomyopathy group (n=27) and a non-ischemic cardiomyopathy group (n=77) according to the cause of heart failure. Before implantation, left ventricular diastolic function was evaluated in all patients using echocardiography. After six months of follow-up, the beneficial effects of cardiac resynchronization therapy were evaluated using a combination of clinical symptoms and echocardiography parameters.

RESULTS:

The ischemic cardiomyopathy group included significantly more patients with restrictive filling than the non-ischemic cardiomyopathy group. The response rate after the implantation procedure was significantly higher in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Degrees of improvement in echocardiography parameters were significantly greater in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Multivariate regression analysis showed that a restrictive filling pattern was an independent factor that influenced responses to cardiac resynchronization therapy.

CONCLUSIONS:

This study again confirmed that the etiology of heart failure affects the beneficial effects of cardiac resynchronization therapy and a lower degree of improvement in ventricular systolic function and remodelling was observed in ischemic cardiomyopathy patients than in non-ischemic cardiomyopathy patients. In addition, systolic heart failure patients with severe diastolic dysfunction had poor responses to cardiac resynchronization therapy. Ischemic cardiomyopathy patients exhibited more severe diastolic dysfunction than non-ischemic cardiomyopathy patients, which may be a reason for the reduced beneficial effect of cardiac resynchronization therapy.

MMP-9 in atrial remodeling in patients with atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common arrhythmia and is associated with significant morbidity and mortality. The impact of matrix metalloproteinases (MMPs) on structural atrial remodeling and sustainment of AF in patients with persistent and permanent AF is unresolved.

OBJECTIVES

The aim was to evaluate MMP-9 and its tissue inhibitor-1 (TIMP-1) as markers of atrial remodeling in patients with persistent AF (PAF) who underwent electrical cardioversion (ECV) and in patients with permanent AF (continuous AF, CAF).

PATIENTS AND METHODS

Plasma levels of MMP-9 and TIMP-1, clinical findings, and echocardiographic parameters were evaluated in 39 patients with AF and in 14 controls with sinus rhythm.

RESULTS

The concentrations of MMP-9 were significantly higher in patients with PAF and CAF compared to controls. There was a significant increase of MMP-9 after ECV in the persistent AF group. The values of TIMP-1 were not significantly different between the groups. In patients with AF, MMP-9 levels were positively related to posterior wall thickness of the LV (r=0.356, P=0.049) and body mass index (r=0.367, P=0.046).

CONCLUSION

Elevated levels of MMP-9 were related to the occurrence and maintenance of AF. This suggests that MMP-9 can be a marker of atrial remodeling in patients with AF. Regulation of the extracellular collagen matrix might be a potential therapeutic target in AF.