Journal of Cardiothoracic-Renal Research最新文献

Mitogen-activated protein kinase (MAPK), also known as the extracellular signal regulated protein kinase (ERK), is a member of a family of serine/threonine kinases which are activated by various growth factors. To date, the activity of ERK and the nuclear dual-specificity tyrosine/threonine protein phosphatase MKP-1, a principal inactivating phosphatase of ERK1/ERK2 in many cell types, in human myocardium with congestive heart failure (CHF) remain undefined. Therefore, the current study was designed to investigate ERK and MKP-1 expression in CHF patients. Cardiac tissue from normal subjects (n = 5) and end-stage CHF patients (n = 5) were obtained during cardiac transplantation. ERK and MKP-1 expression were determined by immunohistochemical staining (IHCS). The staining score (0–4) and positive staining area (0–100%) were determined. Both ERK and MKP-1 were expressed in nuclear and perinuclear regions of cardiomyocytes. In CHF patients, ERK phosphorylation IHCS score and positive staining area were significantly increased in right atrium (RA), left atrium (LA), right ventricle (RV), and left ventricle (LV) compared with normal subject RA, LA, and RV (normal LV tissue was not available). In contrast, MKP-1 IHCS score and positive staining area were significantly decreased in CHF patients RA, LA, RV, and LV myocardium compared with normal subjects. The cardiomyocyte diameter determined by BioQuant system was significantly increased in CHF myocardium compared with normal subjects. These studies suggest that activation of ERK and inhibition of MKP-1 may play a significant pathophysiological role in progression of cardiac hypertrophy and congestive heart failure.

Background

Recent myocardial infarction (≤90 days) is generally considered a contraindication to performing surgical ventricular restoration (SVR). Most surgeons prefer myocardial healing and scar formation to occur before undertaking SVR, although no data exist to support this practice. We analyzed outcomes of patients undergoing SVR following recent myocardial infarction (MI) to determine the utility of SVR in these patients.

Methods

Retrospective review analyzed 69 consecutive SVR patients between January 2002 and June 2005 to determine clinical characteristics, operative data, and postoperative outcomes. Magnetic resonance imaging (MRI) and echocardiography were used to assess cardiac function.

Results

Twenty-two patients (32%) sustained a recent MI in our series. Mean age at operation was 63.5 years, with a M:F of 20:2. Preoperatively all patients carried a diagnosis of congestive heart failure and were classified as New York Heart Association (NYHA) class III or IV. Six patients (27%) required perioperative intra-aortic balloon pump (IABP) support. There was only one operative mortality. Following SVR, mean ejection fraction improved from 26% to 35% (p = 0.02), with a reduction in mean left ventricular end-systolic volume index from 93 mL/m² to 68 mL/m² (p = 0.04). Seventy-three percent (16/22) of patients in preoperative NYHA class III/IV improved to class I/II at follow-up (p < 0.0001). Actuarial survival was 74% at 30 months. Recent MI was not an independent predictor of adverse outcomes following SVR in our series.

Conclusion

Recent MI patients demonstrate significant improvement in ventricular function and NYHA class with acceptable morbidity and mortality following SVR. These findings prompt consideration of expanding the inclusion criteria for SVR to include patients who have sustained a recent MI.