Reperfusion phenomenon is a strong predictor of left ventricular remodeling after acute myocardial infarction

Impact of hypertension on postreperfusion left ventricular recovery in patients with ST-segment elevation myocardial infarction and multivessel coronary artery disease

OBJECTIVE

The aim of this study was to investigate the impact of admission systolic blood pressure (ASBP) and left ventricular (LV) mass on the postreperfusion LV recovery in patients with ST-segment elevation myocardial infarction (STEMI) and concomitant coronary multivessel disease (MVD).

MATERIALS AND METHODS

A retrospective analysis of 12-month postreperfusion LV recovery was performed in 104 patients after primary percutaneous coronary intervention (PPCI). Patients with elevated ASBP (>140mmHg) were assigned to the first group (n=58); with normal ASBP (<140mmHg), to the second group (n=46); with increased myocardial mass index (MMI) (>100g/m(2)), to the third group (n=70); and with normal MMI (<100g/m(2)), to the fourth group (n=34). Severity of MVD was evaluated by the Syntax score. The LV recovery was assessed by evolution of quantitative characteristics of electrocardiography (QRS score, ST score, ECG STEMI stage) and echocardiography (LV ejection fraction, volume and mass indices) registered before and after PPCI, at discharge, and after 1, 6, and 12 months.

RESULTS

There were no significant differences in the baseline QRS and ST scores, ECG STEMI stage, LVEF, MMI, and Syntax score comparing all the patients' groups. The serial ECG criteria showed only a very small impact of ASBP on postreperfusion LV recovery. Only ECG STEMI stage progression was slower in the patients with elevated ASBP. In patients with different MMI, the QRS and ST scores were higher and ECG STEMI stage was lower in patients with increased MMI. LVEF after 1 year was significantly lower in the third group as compared to the fourth group (42.58%±8.25% vs. 46.8%±7.13%, P=0.018).

CONCLUSION

Postreperfusion LV recovery was more related not to ASBP but to the increased LV mass assessed by echocardiography in patients with STEMI and MVD.

Left Ventricular Dyssynchrony After Acute Myocardial Infarction is a Powerful Indicator of Left Ventricular Remodeling

Background and Objectives

Left ventricular (LV) remodeling (LVR) after an acute myocardial infarction (AMI) has important clinical implications. We have investigated the prognostic relevance of ventricular systolic dyssnchrony as an indicator of LVR after an AMI.

Subjects and Methods

We enrolled 92 patients (males, 72.8%; mean age, 61.0±13.0 years) with an AMI who underwent successful percutaneous coronary intervention. We analyzed the baseline characteristics, the laboratory and echocardiographic findings, and we performed follow-up echocardiography 6 months after the AMI. The patients were divided into two groups: 1) the presence of LVR, which was defined as an increment of LV end systolic volume (LVESV) >20% compared with the baseline examination; and 2) the absence of LVR.

Results

Twenty-seven patients (29.3%) developed LVR after a 6 month follow-up. There was no statistically significant difference in the clinical and angiographic findings between the two groups. With respect to the laboratory findings, the LVR group had a higher peak creatine kinase MB (CK-MB) (149.9±155.0 vs. 74.6±69.7 U/L, p=0.001) and troponin-I (70.2±73.3 vs. 43.2±39.5 ng/mL, p=0.024) level than the group without LVR. With respect to echocardiographic findings, the baseline LV ejection fraction (EF) and LVESV were not significantly different (LVESV, 73.0±37.3 vs. 91.3±52.0 mL, p=0.013; and EF, 58.3±13.3 vs. 55.6±11.8%, p=0.329) between the groups with and without LVR, respectively. The degree of LV dyssynchrony, which was assessed by tissue Doppler imaging, was significantly higher in the LVR group than the group without LVR (75.2±43.4 vs. 38.3±32.5 ms), and the degree of LV dyssynchrony was an independent predictor for LVR based on multivariate analysis {hazard ratio (HR)=0.097, p<0.001}. In receiver operating characteristics (ROC) curve analysis, the area under the curve (AUC) was 0.754 and a cutoff value of 45.9 predicted the development of LVR with 74.1% sensitivity and 72.3% specificity.

Conclusion

The presence of LV dyssynchroncy immediately after a myocardial infarction is an important predictive factor for development LVR.

Impact of left ventricular remodeling on ventricular repolarization and heart rate variability in patients after myocardial infarction treated with primary PCI: prospective 6 months follow-up

BACKGROUND

The relation between postinfarction left ventricle remodeling (LVR), autonomic nervous system and repolarization process is unclear. Purpose of the study was to assess the influence of LVR on the early (QTpeak) and late (TpeakTend) repolarization periods in patients after myocardial infarction (MI) treated with primary PCI. The day-to-night differences of repolarization parameters and the relation between QT and heart rate variability (HRV) indices, as well left ventricle function were also assessed.

METHODS

The study cohort of 104 pts was examined 6 months after acute MI. HRV and QT indices (corrected to the heart rate) were obtained from the entire 24-hour Holter recording, daytime and nighttime periods.

RESULTS

LVR was found in 33 patients (31.7%). The study groups (LVR+ vs LVR-) did not differ in age, the extent of coronary artery lesions and treatment. Left ventricle ejection fraction (LVEF) was lower (38%+/- 11% vs 55%+/- 11%, P < 0.001), both QTc (443 +/- 26 ms vs 420 +/- 20 ms, P < 0.001) and TpeakTendc (98 +/- 11 ms vs 84 +/- 12 ms, P < 0.005) were longer in LVR + patients, with no differences for QTpeakc. Trends toward lower values of time-domain (SDRR, rMSSD) HRV parameters were found in LVR+ pts. Day-to-night difference was observed only for SDRR, more marked in LVR-group. Remarkable relations between delta LVEF (6 months minus baseline), delta LVEDV and TpeakTendc were found, with no such relationships for QTpeakc.

CONCLUSIONS

The patients with LVR have longer repolarization time, especially the late phase-TpeakTend, which represents transmural dispersion of repolarization. Its prolongation seems to be related to local attributes of myocardium and global function of the left ventricle but unrelated to the autonomic nervous influences. Remodeling with moderate LV systolic dysfunction is associated with insignificant decrease in HRV indices and preserved circadian variability.

Clinical validity of longitudinal pre-ejectional myocardial velocity for identifying the transmural extent of viable myocardium: early after reperfusion of an infarct-related coronary artery

BACKGROUND

Positive longitudinal pre-ejectional velocity (+PEVL) was recently reported to be a reliable index of myocardial recovery early after successful revascularization in myocardial infarction (MI); that is, it recognizes the transmural extent of viable myocardium. The applicability of PEVL in the real-world clinical setting for identifying the transmural extent of viable myocardium in reperfused recent MI was assessed.

METHODS AND RESULTS

Using tissue Doppler imaging, the resting basal and mid myocardial PEVLs were determined within 3 days after revascularization in 41 consecutive patients with recent MI. Infarct thickness was semi-quantified using delayed gadolinium-enhanced magnetic resonance imaging (MRI) at baseline and at 6-month follow up to differentiate transmural from nontransmural MI. The proportion of segments showing the presence of +PEVL was not significantly changed as infarct thickness increased (p=0.2), with 66.2% having +PEVL even in segments involving >75% transmural infarction. Moreover, +PEVL was found in a large fraction of segments with akinesia (70.4%). Specificity and negative predictive value of +PEVL for assessing infarct nontransmurality were disappointingly low (32.0% and 26.9%, respectively). All of these results were not altered when the 6-month follow-up MRI was done.

CONCLUSIONS

+PEVL cannot be regarded as a reliable marker for predicting the transmural extent of viable myocardium in recent MI.

Relationship Between Peripheral Monocytosis and Nonrecovery of Left Ventricular Function in Patients With Left Ventricular Dysfunction Complicated With Acute Myocardial Infarction

BACKGROUND

Although ischemic heart failure is a major cause of mortality after acute myocardial infarction (AMI), the factors that may influence the nonrecovery of left ventricular function (LVF) after an AMI are still unclear. The aim of this study was to identify predictors of nonrecovery of LVF in patients with left ventricular (LV) dysfunction (defined as an echocardiographic ejection fraction (EF)<40%) complicated with AMI who undergo successful primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

LVF recovery was defined as improvement of LVEF more than 10% compared with baseline LVEF at follow-up. One hundred and eight patients with LV dysfunction after AMI were divided into 2 groups according to the LVF recovery at follow-up: patients with LVF recovery (n=64) vs patients without LVF recovery (n=44). The follow-up LVEF was measured at 8+/-4 months after PCI. Patients without LVF recovery were older (76+/-13 years vs 59+/-14 years, p=0.023) and the baseline peak monocyte count, creatine kinase, and troponin I levels were significantly higher in patients without LVF recovery than in patients with LVF recovery. Delta LVEF (follow-up LVEF-baseline LVEF) correlated with baseline peak monocyte count (r=-0.417, p<0.001), baseline peak creatine kinase (r=-0.269, p=0.005), and baseline peak troponin I levels (r=-0.256, p=0.007). Multivariate analyses showed that baseline peak monocyte count and old age were the independent predictors of nonrecovery of LVF (hazard ratio; 3.38, 95% confidence interval (CI): 1.16-5.43, p=0.012, and hazard ratio; 2.38, 95% CI: 1.09-4.87, p=0.025, respectively).

CONCLUSION

Peripheral monocytosis is associated with nonrecovery of LVF in patients with LV dysfunction complicating an AMI who underwent successful primary PCI. These results suggest an important role of monocytes in the expansion of the infarct and the development of chronic ischemic heart failure after reperfusion therapy.

Tumor-Necrosis-Factor-.ALPHA.-Gene-Deficient Mice Have Improved Cardiac Function Through Reduction of Intercellular Adhesion Molecule-1 in Myocardial Infarction

BACKGROUND

Tumor necrosis factor (TNF)-alpha is linked to the pathogenesis of cardiovascular diseases, but how it affects myocardial infarction (MI), so the present study examined the effects of TNF-alpha and the involvement of intercellular adhesion molecule (ICAM)-1 on MI.

METHODS AND RESULTS

Left coronary arteries of C57BL/6 wild type (WT) and TNF-alpha knockout (KO) mice were ligated and the mice were killed 1, 3, and 7 days later. Fractional shortening on echocardiography of the KO mice was significantly higher than that of the WT mice from day 1 to 7 (p<0.01). The ICAM-1 mRNA in the infarcted area of the KO mice was significantly lower than that of the WT from day 1 (p<0.01) to 7. In immunohistochemistry, the expression of ICAM-1 was weaker in the KO than in the WT mice. The number of neutrophils in the KO mice peaked at day 1, but even this peak level failed to reach the levels in the infarcted (p<0.01) and peri-infarcted areas (p<0.05) in the WT. The number of macrophages in the KO mice peaked at day 7, but this peak level failed to reach the levels in the infarcted (p<0.01) and peri-infarcted areas (p<0.05) in the WT.

CONCLUSION

In a permanent occlusion model of MI TNF-alpha decreased cardiac function and ameliorated myocardial remodeling through the induction of ICAM-1.

Multidetector Row Computed Tomography Noninvasively Assesses Coronary Reperfusion After Thrombolytic Therapy in Patients With ST Elevation Myocardial Infarction

BACKGROUND

The study objective was to assess the efficacy of 16-slice multidetector row computed tomography (MDCT) in estimating residual stenosis and successful reperfusion after thrombolysis in patients with ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

A total of 31 patients with STEMI underwent MDCT scanning within 6 h (mean 4.6+/-1.1) after thrombolysis and the results for detection of significant residual stenosis and distal flow of the infarct-related artery were compared with those from conventional coronary angiography (CCAG) performed within 24 h (mean 12.1+/-5.6) after the MDCT scan. Successful reperfusion was defined as Thrombolysis In Myocardial Infarction flow 2 or 3 on CCAG and full contrast enhancement of the distal artery landmarks on MDCT. A final analysis was performed using 24 patients (312 segments). MDCT had a positive predictive value of 73.3% and a negative predictive value of 95.1% for detecting significant residual stenosis. It accurately estimated 17 of 18 patients (94.4%) with successful reperfusion and 5 of 6 (83.3%) with failed reperfusion on the basis of comparison with CCAG.

CONCLUSIONS

MDCT demonstrated high accuracy not only for the detecting residual stenosis, but also for assessing successful reperfusion after thrombolytic therapy in patients with STEMI.