In-hospital heart failure, first-year ventricular dilatation and 10-year survival after acute myocardial infarction

Ventricular reshaping with a beating heart implant improves pump function in experimental heart failure

OBJECTIVE

The left ventricle remodels from an ellipsoidal/conical shape to a spherical shape after a myocardial infarction. The spherical ventricle is inefficient as a pumping chamber, has higher wall stresses, and can lead to congestive heart failure. We sought to investigate if restoring physiological ventricular shape with a beating heart implant improves pump function.

METHODS

Rats were induced with a myocardial infarction, developing left ventricular dilatation and dysfunction, and becoming spherical over 3 weeks. Thereafter, they were randomized to undergo left ventricular reshaping with a beating heart implant (n = 19) or continue follow-up without an implant (n = 19). Biweekly echocardiography was performed until 12 weeks, with half the rats euthanized at 6 weeks and remaining at 12 weeks. At termination, invasive hemodynamic parameters and histopathology were performed.

RESULTS

At 3 weeks after the infarction, rats had a 22% fall in ejection fraction, 31% rise in end diastolic volume, and 23% rise in sphericity. Transventricular implant reshaping reduced the volume by 12.6% and sphericity by 21%, restoring physiologic ventricular shape and wall stress. Over the 12-week follow-up, pump function improved significantly with better ventricular-vascular coupling in the reshaped hearts. In this group, cardiomyocyte cross-section area was higher and the cells were less elongated.

CONCLUSIONS

Reshaping a postinfarction, failing left ventricle to restore its physiological conical shape significantly improves long-term pump function.

Age- and Body Size-Adjusted Left Ventricular End-Diastolic Dimension in a Japanese Hospital-Based Population

BACKGROUND

Using the normal values for the East Asian population, we evaluated age- and body size-adjusted left ventricular end-diastolic dimension (LVEDD) and its prognostic impact in a hospital-based population in Japan. Methods and Results: We retrospectively analyzed data obtained from 4,444 consecutive patients who had undergone both transthoracic echocardiography and electrocardiography at Kitano Hospital in 2013. Those who presented with a history of previous episodes of myocardial infarction and severe or moderate valvular disease or with low ejection fraction (<50%) were excluded from the analysis. We calculated LVEDD adjusted by age and body surface area. A total of 3,474 patients were categorized into 3 groups: 401 with large adjusted LVEDD, 2,829 with normal adjusted LVEDD, and 244 with small adjusted LVEDD. Mean patient age in the large, normal, and small adjusted LVEDD groups was 66.6±18.4, 65.6±15.7, and 62.1±15.5 years, respectively (P<0.001). After adjusting for confounding factors, the excess adjusted 3-year risk of primary outcome of large adjusted LVEDD relative to normal LVEDD was significant (HR, 1.40; 95% CI: 1.08-1.78). The risk for primary outcomes of small adjusted LVEDD relative to normal adjusted LVEDD was significantly lower (HR, 0.55; 95% CI: 0.34-0.85).

CONCLUSIONS

Adjusted large LVEDD has a deleterious impact on long-term mortality, whereas small LVEDD carried a significantly lower risk.

N-terminal pro-brain natriuretic peptide in the elderly with myocardial infarction

BACKGROUND

The myocardial infarction (MI) results in the change of the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) in blood. In addition, attention is paid to the dependence of NT-proBNP levels on the patients' age. However, the behavior of natriuretic peptide levels has not been recognized well enough in the elderly with MI treated with invasive methods.

HYPOTHESIS

The aim of the study was to estimate the effect of age on NT-proBNP levels in patients with first MI, and treated with primary percutaneous coronary intervention (PCI) with complete coronary revascularization.

METHODS

One hundred and sixty-one consecutive patients with first ST-elevation MI, and treated with primary PCI with stent implantation (occlusion in infarct-related artery was the patient's only lession) were included. Determination of NT-proBNP level and echocardiography were performed on the 4th-5th day of MI.

RESULTS

Thirty-seven patients (23%) aged>or=65 y were considered as a study group. The NT-proBNP levels were nearly 4-fold higher in older patients than in younger patients. Only systolic and diastolic dysfunction, mitral regurgitation, troponin T levels, and glomerular filtration rate (GFR) were independent risk factors of the occurrence of elevated NT-proBNP concentration above median.

CONCLUSIONS

The patients' age was not a factor independently affecting the increase of NT-proBNP level above the median in patients with first MI and treated successfully with primary PCI. Independently associated elevated levels of NT-proBNP were as follows: presence of diastolic dysfunction, mitral regurgitation, left ventricular systolic dysfunction, troponin T concentration, and GFR.

Impact of the number of image planes of real-time three-dimensional echocardiography on the accuracy of left atrial and ventricular volume measurements

Real-time three-dimensional (3D) echocardiography (RT-3DE) has emerged as a new technique in measuring left atrial and ventricular volume. However, the impact of cutting planes of RT-3DE on the accuracy of volume measurement in patients with a normal or enlarged heart is still unknown. We enrolled 30 normal subjects (control group) and 30 patients with heart failure (patient group). RT-3DE was performed to measure maximal volume of the left atrium (LAVmax) and left ventricular end-diastole volume (LVEDV) with 2-, 4-, 8- and 16-cutting planes, compared with cardiac magnetic resonance imaging (CMRI). In both groups, LAVmax by RT-3DE using 2- and 4-cutting planes was significantly underestimated (mean difference: -10.4 +/- 16.6 mL, p = 0.001 and -8.8 +/- 14.2 mL, p = 0.002 in the control group and -13.4 +/- 19.6 mL, p = 0.001 and -11.2 +/- 17.5 mL, p = 0.001 in the patient group, respectively). These differences became nonsignificant when 8- and 16-cutting planes were adopted (mean difference: -2.1 +/- 7.6 mL and -1.9 +/- 7.4 mL in the control group and -2.7 +/- 8.4 mL and -2.2 +/- 8.3 mL in the patient group, respectively). The agreement for LVEDV was acceptable when 4- or more cutting planes were used in the control group and when 8- or 16-cutting planes were used in the patient group. The time expense for data analysis of LAVmax with 8-image planes was only 7 +/- 4 min in the control group and 6 +/- 5 min in the patient group, almost halving that of the 16-image planes. Similarly, 4- and 8-cutting planes were required for an accurate measurement of LVEDV in the control and patient groups, respectively. In conclusion, RT-3DE with 8-cutting planes is both accurate and timesaving for measurement of LAVmax and LVEDV in patients with normal or enlarged left atria and ventricles.

Early changes in left ventricular volume and function are predictors for long-term remodeling in patients with acute transmural myocardial infarction and preserved systolic function

BACKGROUND

We sought to describe the degree of long-term left ventricular (LV) remodeling after acute transmural myocardial infarction with preserved LV systolic function, and to evaluate whether Doppler echocardiographic parameters in the early phase could predict this process.

METHODS

A total of 60 patients without heart failure and with LV ejection fraction > or = 0.40 (mean 0.48 +/- 0.054), were followed up with Doppler echocardiographic examinations at baseline, 3 months, and 1 and 2 years.

RESULTS

There was a significant increase in LV end-diastolic volume index of 7% (P =.006) and LV end-systolic volume index of 8% (P =.03), and no change in ejection fraction. This remodeling was confined to 7 patients (12%) with a significant increase in LV end-diastolic volume index above 20 mL/m(2). There was also a significant increase in the deceleration time of both the early mitral filling wave (Delta early mitral filling wave = 58 milliseconds, P <.0005) and the diastolic forward component of pulmonary venous flow (Delta diastolic forward component of pulmonary venous flow = 61 milliseconds, P <.0005), and a shift in filling pattern with increasing prevalence of abnormal relaxation. Changes in end-diastolic volume index were predicted by baseline early mitral filling wave less than 100 milliseconds, but the most powerful predictors of 2-year remodeling were volume changes at 3 months.

CONCLUSION

Twelve percent of patients with Q-wave infarction and ejection fraction > or = 0.40 experienced significant LV dilatation at 2 years, and this late remodeling was partly related to baseline filling characteristics.