Reversible left ventricular dysfunction

Value of two-dimensional strain imaging in prediction of myocardial function recovery after percutaneous revascularization of infarct-related artery

BACKGROUND

Speckle tracking is integrated into echocardiographic systems for evaluation of left ventricular (LV) function by means of automated function imaging (AFI). This study aimed at evaluating role of AFI-based strain in predicting postpercutaneous coronary intervention (PCI) LV function recovery.

METHODS

Fifty patients with anterior wall myocardial infarction and impaired LV ejection fraction (LVEF) were prospectively enrolled. All patients showed positive viability results concerning left anterior descending (LAD) artery territory using low-dose dobutamine stress echocardiography (LDSE). All patients underwent strain imaging using AFI (before and after PCI).

RESULT

Mean age of the study population was 56.2 ± 5.4 years, 34 (68%) being males. 24 (48%) patients showed post-PCI LV function recovery after 4 months. They showed higher pre-PCI LVEF and AFI-based strain values. Logistic regression analysis presented baseline LVEF as an independent predictor of LV function recovery (Odds ratio = 0.7026, 95% CI: 0.54-0.93). A pre-PCI AFI strain value of -4.5% (sensitivity: 84% and specificity: 75%) for LAD territory and -9.5% (sensitivity and specificity of 50%) for global LV predicted LV function recovery.

CONCLUSION

Assessment of global and territorial LV strains using AFI; is of added value upon viability assessment using LDSE. Higher baseline LVEF and strain values are associated with post-PCI LV function recovery.

Cardioprotective effects of oral nicorandil use in diabetic patients undergoing elective percutaneous coronary intervention

OBJECTIVE

This study sought to evaluate the cardioprotective role of oral nicorandil (a hybrid between the nitrates and adenosine triphosphate [ATP] sensitive potassium channel activators) in diabetic patients undergoing elective percutaneous coronary intervention (PCI).

BACKGROUND

Myocardial injury commonly occurs during PCI. Several agents that mimic ischemic preconditioning could help minimize this phenomenon.

METHODS

One hundred diabetic patients with stable angina were prospectively enrolled, then randomly assigned to receive oral nicorandil: 20 mg once daily (group A, 50 patients) or placebo (group B, 50 patients) 1 week before and 6 months after PCI. Cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) levels were measured before and 6, 12, and 24 hours post-PCI.

RESULTS

Mean age of the study cohort was 59.8 ± 5.8 years (males = 68%). cTnI level was significantly lower in group A (6 hours: 7.3 ± 0.3 vs. 14.5 ± 0.4 pg/mL; 12 hours: 12.7 ± 0.7 vs. 25.3 ± 0.5 pg/mL; and 24 hours: 7.7 ± 0.5 vs. 15.0 ± 0.4 pg/mL, P < 0.001). After 6 months, the same group showed significantly higher left ventricle ejection fraction (LVEF%), that is, 63.5 ± 7.7% versus 56.5 ± 8.3% (P < 0.05), with a trend toward lower incidence of major adverse cardiac events (MACE).

CONCLUSION

In diabetic patients undergoing elective PCI, nicorandil intake was associated with decreased incidence of PCI-related myocardial injury and improvement of LVEF% after 6 months.

Atropine first is safer than conventional atropine administration in older people undergoing dobutamine stress echocardiography

OBJECTIVE

Early injection of atropine during dobutamine stress echocardiography (DSE) has been demonstrated in retrospective analyses to reduce the duration and dose of dobutamine infusion, while preserving a similar diagnostic accuracy with a lower incidence of adverse effects. This study explores the safety of using atropine as a start drug before dobutamine infusion (ADSE protocol) in comparison with the conventional protocol (DASE protocol) in older patients undergoing DSE for ischemia evaluation.

METHODS

One hundred consecutive older patients were prospectively enrolled. When eligible, they were randomly assigned to undergo either the DASE protocol (group A, 50 patients) or the ADSE protocol (group B, 50 patients) when atropine (1.0 mg) was first administered 3 min before dobutamine infusion followed by 0.5 mg increments (maximum 1.0 mg) thereafter. Patients were monitored for adverse drug effects. Test duration was calculated.

RESULTS

The mean age of the whole study cohort was 67.8±4.3 years and 58 (58%) were men. Patients in group A had longer test duration (21.8±1.3 versus 13.7±0.77 min, p<0.001) and higher mean dobutamine infusion rate (39±8.2 versus 28.2±9.5 μg/kg/min, p<0.001). The two groups received a similar total dose of atropine. Group A patients showed significantly higher incidence of extrasystoles, nonsustained ventricular tachycardia and severe hypotension (p<0.05).

CONCLUSION

In older patients undergoing DSE, using atropine as a start drug, that is, adopting the ADSE protocol, is associated with shorter test duration, lower mean dobutamine infusion rate and consequently fewer adverse effects.

Cardioprotective Effects of Oral Trimetazidine in Diabetic Patients With Anterior Wall Myocardial Infarction Treated with Thrombolysis

Background

Trimetazidine is an anti-ischemic agent with anti-oxidant activity. This study sought to evaluate the impact of oral trimetazidine on extent of myocardial damage in diabetic patients who were presented with anterior wall ST-segment elevation myocardial infarction (STEMI).

Methods

One hundred patients were prospectively enrolled, and then randomly assigned to receive oral trimetazidine (70 mg then 35mg bid) (group A, 50 patients) or placebo (group B, 50 patients), starting before thrombolysis. Serum creatine kinase-T and MB (CK-T and CK-MB) were measured serially. Degree of ST-segment resolution was recorded after 90 minutes. Left ventricle ejection fraction (LVEF) was assessed at baseline and after 6 months. Adverse events were recorded after thrombolysis and 6 months later.

Results

Mean age of the study cohort was 59.05 ± 3.8 years (males: 60%). After 24 hours, 45 (90%) patients in group A vs. 10 (20%) patients in group B showed peaking of CK-T and CK-MB levels (P < 0.05). Both biomarkers’ levels were significantly higher in the placebo group at different sampling times. Complete resolution of ST-segment elevation was recorded in 35 (70%) patients in group A vs. 18 (36%) patients in group B (P < 0.05). Six months later, group A showed higher LVEF and fewer cardiac adverse events (P < 0.05).

Conclusion

In diabetic patients receiving thrombolytic therapy for anterior wall STEMI, oral trimetazidine dosing was associated with less myocardial damage, earlier successful reperfusion, improvement of LVEF and less cardiac adverse events.

Predictors of contractile recovery after revascularization in patients with anterior myocardial infarction who received thrombolysis

BACKGROUND

Identification of viable myocardium after myocardial infarction has gained paramount importance with the current progress in coronary revascularization.

OBJECTIVE

To explore the prognostic power of certain patient characteristics to predict myocardial contractile recovery after revascularization in patients presenting with acute anterior ST elevation myocardial infarction (STEMI) who received thrombolytic therapy.

METHODS

Seventy-three consecutive patients presenting with first acute anterior STEMI who had received thrombolytic therapy and had significant coronary stenosis or occlusion of the infarct-related artery amenable for revascularization were enrolled. All patients underwent echocardiographic assessment of regional wall motion and left ventricular ejection fraction. Patients underwent coronary revascularization by either percutaneous angioplasty or surgical bypass. Echocardiography was repeated two to three months following revascularization. Patients were classified into two groups: group 1 had evidence of contractile recovery after revascularization at follow-up echocardiography and group 2 had no such evidence of recovery.

RESULTS

Predictors of contractile recovery after revascularization included a shorter time from symptom onset to the institution of thrombolytic therapy, a lower baseline wall motion score index, the presence of grade 3 collaterals to the infarct-related artery and the use of beta-blockers. Instead, the presence of diabetes mellitus and a totally occluded infarct-related artery predicted poor contractile recovery.

CONCLUSIONS

Myocardial contractile recovery after revascularization in patients presenting with first acute anterior STEMI may be predicted by the absence of diabetes, a shorter time from symptom onset to thrombolytic therapy, the use of beta-blockers, a lower initial wall motion index score and the presence of collaterals to the infarct-related artery.

Incremental Prognostic Value of Stress Echocardiography Over Clinical and Stress Electrocardiographic Variables in Patients With Prior Myocardial Infarction: "Warranty Time" of a Normal Stress Echocardiogram

BACKGROUND

Patients with prior myocardial infarction (MI) are at increased risk of subsequent cardiac events (MI or cardiac death). The incremental prognostic value and warranty time of a normal stress echocardiogram in this high-risk population is not well defined.

METHODS

We evaluated 251 consecutive patients (62 +/- 11 years; 64% males) with remote history of MI (>6 weeks) undergoing stress echocardiography (83% dobutamine). Ischemia was defined as a new reversible wall motion abnormality and/or biphasic response. Follow-up for up to 4 years (mean 2.9 +/- 1.0 years) for confirmed MI (n = 7) and cardiac death (n = 15) were obtained.

RESULTS

Stress echocardiography effectively risk stratified patients into normal versus abnormal subgroups (Event rate 0.8% per year vs 4.2% per year; P = 0.01; RR = 5.6, 95% CI = 1.3-24.7). In patients with a normal stress echocardiogram, the event rate at the end of 6, 12, and 18 months were <1% per year. After 18 months the event rate in patients with a normal stress echocardiogram increased greatly (>1% per year). Stress echocardiography yields incremental prognostic value over clinical and stress electrocardiographic variables (Global chi-square increased from 12.4 to 25 to 31.1, P < 0.0001 both groups).

CONCLUSIONS

Stress echocardiography yields appropriate risk stratification and prognosis and provides incremental prognostic value over clinical and stress electrocardiographic variables even in patients with prior MI. A normal stress echocardiogram portends a benign prognosis (<1% event rate/year) for up to 18 months.

Stress Function Index, a Novel Index for Risk Stratification and Prognosis Using Stress Echocardiography

OBJECTIVES

The purpose of the study was to define an appropriate parameter for risk stratification and prognosis of patients undergoing stress echocardiography.

BACKGROUND

Among stress echocardiography variables, peak wall-motion score index (WMSI) and ejection fraction (EF) have been shown to be independent and significant predictors of cardiovascular morbidity and mortality. Data on the impact and importance of each parameter in risk stratification and prognosis are limited.

METHODS

We evaluated 1560 patients (59 +/- 13 years; 51% men) undergoing stress echocardiography (36% treadmill, 64% dobutamine). Peak WMSI was derived from the cumulative sum of 16 left ventricular segments divided by sum of visualized segments at peak stress. The ratio of peak WMSI to EF was calculated for the entire cohort. Based on this ratio and using the receiver operating characteristic curve, patients were divided into 3 groups: low- (< 1.9), intermediate- (1.9-3.1), and high- (> 3.1) risk subgroups. Follow-up (2.8 +/- 1.1 years) for confirmed myocardial infarction (n = 26) and cardiac death (n = 38) were obtained.

RESULTS

Stress echocardiography effectively risk stratified patients into low- (0.7%/y), intermediate- (2.0%/y), and high- (4.4%/y) risk subgroups (P < .0001) based on the ratio of peak WMSI to EF. Cox proportional hazard model showed that risk stratification based on the ratio of peak WMSI to EF (global chi2 = 106.05; P < .0001) provided incremental value beyond that provided by risk stratification by peak WMSI (global chi2 = 79.23; P < .0001) or risk stratification by EF alone (global chi2 = 87.12; P < .0001).

CONCLUSIONS

The ratio of peak WMSI to EF (stress function index) provides best incremental prognostic value and effectively risk stratifies patients into low-, intermediate-, and high-risk subgroups and is better than risk stratification by either peak WMSI or EF alone. The results of stress echocardiography should routinely combine peak WMSI and EF for effective risk stratification.