Electrophysiological effects of intracoronary transplantation of autologous mesenchymal and endothelial progenitor cells.

AIMS: Autologous stem cell transplantation has been successfully used for repair of infarcted myocardium, but concerns have been raised regarding its pro-arrhythmic potential. This study aimed at using electrophysiological assessment, and the monitoring and data storage capacity of implanted cardioverter defibrillators (ICDs), in order to evaluate the possible proarrhythmic potential of stem cell transplantation. METHODS: Five patients with a history of previous anteroseptal myocardial infarction and an implanted ICD for ventricular arrhythmias underwent intracoronary transplantation of autologous bone marrow-derived and culture-expanded mesenchymal stem cells in combination with endothelial progenitors. RESULTS: There was evidence of myocardial repair in three patients in whom segmental left ventricular wall motion improvement was detected on stress echocardiography. Before stem cell transplantation, clinical non-sustained ventricular tachycardia and inducible monomorphic ventricular tachycardia, or ventricular flutter at electrophysiology study were demonstrated in all patients. At 16-36 months follow-up, interrogation of the ICD failed to detect sustained or non-sustained ventricular arrhythmia in any patient. At repeat electrophysiology study, sustained ventricular arrhythmia was induced in two patients. CONCLUSION: Intracoronary transplantation of autologous mesenchymal and endothelial progenitor cells does not appear to be arrhythmogenic in humans. Further studies are needed on this important clinical issue.

Acute changes in N-terminal pro-brain natriuretic peptide induced by dobutamine stress echocardiography.

AIMS: Aim of the study was to determine the effect of dobutamine stress echocardiography (DSE)-induced ischemia on circulating levels of N-terminal fragment of B-type natriuretic peptide (NT-pro-BNP). METHODS AND RESULTS: One hundred and twenty-eight patients underwent DSE for the evaluation of known or suspected coronary artery disease. NT-pro-BNP levels were measured before and 1h after completion of DSE. NT-pro-BNP levels were similar before and after DSE regardless of whether patients had (123+/-101.8 vs. 124.2+/-108.3, p=NS) or did not have inducible ischemia (96.5+/-70.5 vs. 100.5+/-71.1, p=NS). Patients with inducible myocardial ischemia had no different NT-pro-BNP levels compared to patients without inducible ischemia both before (123+/-101.8 vs. 96.5+/-70pg/ml, p=0.37) and after DSE (124.2+/-108.3 vs. 100.5+/-71.1pg/ml, p=0.55). Patients with severe inducible ischemia had significantly higher NT-pro-BNP levels compared to patients with mild or moderate inducible ischemia and patients without inducible ischemia, both before (208.5+/-125.5 vs. 96+/-78.9 vs. 96.5+/-70pg/ml, p=0.017 and p=0.025, respectively) and after DSE (212.5+/-138.1 vs. 94.8+/-81.1 vs. 100.5+/-71.1pg/ml, p=0.015 and p=0.023, respectively). NT-pro-BNP levels before DSE could be independently predicted by age (p<0.0001), presence of diabetes mellitus (p=0.002), and ejection fraction (p=0.005), but not DSE inducible ischemia. CONCLUSION: NT-pro-BNP is not affected by DSE-induced ischemia and cannot be used in clinical practice to improve diagnostic accuracy of DSE.

Does diagnostic coronary angiography induce significant coronary microembolization in stable, ischemic patients? A prospective study.

BACKGROUND: Although microembolization during percutaneous coronary interventions is a frequent event, the extent of possible microembolization during diagnostic coronary angiography is unknown. The aim of the study was to investigate whether diagnostic coronary angiography results in coronary microembolization and consequent subtle, subclinical myocardial necrosis with enzyme elevations. METHODS: Fifty-three consecutive patients underwent diagnostic coronary angiography due to inducible ischemia. Creatine kinase MB isoenzyme (CK MB) and cardiac troponin I (cTnI) were used as sensitive surrogate markers of myocardial necrosis. Serial measurements, before, and 6 and 24 hours following a diagnostic procedure, were performed. RESULTS: Baseline cTnI was below the limits of detection in all patients (<0.20 ng/mL), except for one patient with 1.31 ng/mL. Baseline median CK-MB was 1.05 ng/mL (interquartile range, 0.80-1.56 ng/mL) (Fig. 1). Both at 6 and 24 hours, no patients had any increase in cTnI, with the exception of a minor increase to 0.22 ng/mL at 24 hours in one patient. At 6 hours, 25 patients had decreases in CK MB, while 22 had increases (exact P = 0.77). At 24 hours, 26 patients had decreases in CK MB and 19 patients had increases. CONCLUSIONS: Detectable embolization with subsequent subclinical myonecrosis is an unlikely event.

Proarrhythmic effects of atrial fibrillation ablation techniques.

BACKGROUND: The incidence of proarrhythmia induced by ablation for atrial fibrillation (AF) is not entirely known. We describe the incidence and management of atrial arrhythmias occurring after various techniques for the ablative therapy of AF. METHODS: Ninety-four patients with paroxysmal AF underwent ostial pulmonary vein (PV) ablation (n=54) or circumferential ablation around the PV ostia (n=40). RESULTS: Atrial tachycardia or flutter was detected during the first 6 months after AF ablation in 10 patients. Atrial arrhythmia was more common among patients who underwent circumferential ablation or circumferential with lines (18.2% and 22.2%, respectively) than in those who were treated with other techniques (p = 0.037). The incidence of atrial tachycardia or flutter among patients who underwent ostial ablation or ostial with lines was 2.4% and 8.3%, respectively. No difference was observed in the risk of atrial arrhythmia between patients who underwent ablation with or without additional lines, either ostial (p = 0.398) or circumferential (p = 0.999). Re-ablation was performed in 7 patients with sustained atrial arrhythmia. At 6 months, no recurrence of atrial tachycardia or flutter was.seen in 6 of these patients, nor in 3 patients with non-sustained atrial tachycardia or flutter. CONCLUSIONS: The incidence of atrial tachycardia or flutter following AF ablation is lower for ostial than for circumferential ablation. The addition of lines along the mitral isthmus and between the superior PVs does not significantly affect the risk of ablation-induced arrhythmia. Non-sustained atrial tachycardia or flutter during or early after AF ablation procedures does not require additional ablation.

Handgrip-enhanced myocardial fractional flow reserve for assessment of coronary artery stenoses.

BACKGROUND: Fractional flow reserve (FFR) may yield false-negative results in up to 12% of lesions tested, and there is a zone of uncertainty at borderline values. METHODS: Forty-eight patients were investigated by means of dobutamine stress echocardiography (DSE), coronary angiography, and FFR assessment of 48 coronary lesions before, during, and immediately after handgrip exercise. RESULTS: Mean FFR values were lower during and immediately after handgrip exercise as compared with baseline (0.86 +/- 0.09 vs 0.87 +/- 0.08 vs 0.88 +/- 0.08, P < .05, respectively). The sensitivity of FFR < or = 0.75 for predicting myocardial ischemia on DSE was 17.6% before handgrip exercise, 52.9% during, and 35.5% immediately after exercise. The specificity of FFR < or = 0.75 before, during, and immediate after exercise was 100%, 93.5%, and 96.8%, respectively. In 10 patients, FFR values > 0.75 before handgrip became < or = 0.75 during or immediately after handgrip exercise (P = .01). All these patients had angina and/or DSE indicating ischemia in the territory of the vessel studied, and underwent coronary intervention. At 6 months follow-up, all patients were asymptomatic with negative DSE tests. CONCLUSIONS: The addition of handgrip exercise can significantly lower the FFR and potentially improve its ability to detect physiologically significant stenoses.

Sirolimus-versus paclitaxel-eluting stents: a comparison of two consecutive series in routine clinical practice.

BACKGROUND: We compared two consecutive series of patients treated with sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES). METHODS: Two hundred and ninety-five patients with 590 coronary lesions were treated with 274 SES and 379 PES. Patients with symptoms or positive dobutamine stress echocardiography were subjected to repeat coronary angiography. RESULTS: During a follow-up of 13.3 +/- 5.7 months, the incidence rate of major adverse cardiac events (MACE) was 4.1%, including, 1 death, 4 Q-wave myocardial infarctions, 2 late angiographic stent thromboses, 3 subacute stent thromboses, and 11 target vessel revascularizations (TVR), and was not significantly different between SES (n = 5) and PES (n = 7). Stent overlapping was found to be an independent predictor of both MACE (odds ratio = 0.078, P = 0.02) and TVR (odds ratio = 0.077, P = 0.02). Follow-up symptoms- or ischemia-driven angiography was performed in 45 patients. Only vessel size was a predictor of stent restenosis (P = 0.02), independent of stent type. Late loss was independently predicted by postdilatation of stent (beta =-0.24, P = 0.03), but not by type of stent (P = 0.14) or other parameters. Edge restenosis was seen in 8 patients subjected to lesion predilatation. The restenosis pattern after SES implantation was focal, but diffuse (n = 1) or proliferative (n = 1) restenosis, and in-stent aneurysm formation (n = 1) was also seen with PES. CONCLUSIONS: Despite a trend for a higher incidence of MACE with PES, no significant differences between the two stent types were detected. Diffuse restenosis was seen only with PES, and edge restenosis only in lesions with balloon predilatation before stent implantation. Stent overlapping was an independent predictor of both TVR and MACE.

Direct versus predilatation drug-eluting stenting: a randomized clinical trial.

BACKGROUND: Direct stenting without balloon predilatation has been shown to be feasible and safe with drug-eluting stents, but no randomized comparisons between the two strategies exist. This study was designed to compare direct stenting with balloon predilatation followed by stent placement using only drug-eluting stents. METHODS: One hundred and sixty-six consecutive coronary lesions in 95 consenting patients (mean age 59 +/- 11 years; 12 women) were randomly assigned to direct stenting (n = 88), or balloon predilatation followed by stenting (n = 78), using sirolimus- or paclitaxel-eluting stents. RESULTS: All procedures were uneventful. Crossover to balloon predilatation was necessary in 6 (7%) lesions randomized to direct stenting. During a 12-month follow up period, ischemia-driven angiography was performed in 13 patients. By intention to treat analysis, target lesion revascularization was required in 4 lesions, all of which were randomized to the predilatation group (p = 0.04). CONCLUSIONS: Direct stenting was feasible in up to 93% of attempted lesions. A strategy of direct stenting resulted in a significantly lower rate of target lesion revascularization over a 12-month follow-up period compared to balloon predilatation followed by stenting.

Drug-eluting stents: immediate and long-term results.

INTRODUCTION: In this study we present our findings from a series of patients who underwent coronary angioplasty and implantation of drug-eluting stents with rapamycin or paclitaxel. METHODS: Two hundred and twenty-three consecutive patients with 343 coronary lesions underwent angioplasty with implantation of 220 rapamycin-eluting stents (Cypher) and 297 paclitaxel-eluting stents (Taxus). RESULTS: During the follow up period, 32 patients with 49 lesions had a new coronary angiographic examination because of ischaemia recurrence. The mean follow up time for these patients was 7.2 +/- 3.0 months (2.9-17.1 months). Seven patients showed angiographic restenosis (>50% diameter stenosis) in 9 lesions where stents had been implanted. The type of restenosis was focal in 7 of those lesions (in one it was multifocal), usually at the proximal edge of the stent. In 2 lesions the restenosis was diffuse (1 in-stent, 1 extending beyond the stent margins). The incidence of major adverse coronary events was 4.4% (10 patients: 1 death, 1 non-Q myocardial infarction, 1 Q myocardial infarction and 7 target vessel revascularisation procedures). CONCLUSIONS: Our findings demonstrate that drug-eluting stents can be used in routine clinical practice, regardless of the type of stenosis and the patients' clinical characteristics. The type of restenosis is mainly focal, though diffuse restenosis may also occur when complex lesions are treated with multiple stents.

Sustained ventricular tachycardia induced by dobutamine stress echocardiography: a prospective study.

AIMS: To investigate the prognostic significance and electrophysiological characteristics of dobutamine stress echo (DSE)-induced sustained monomorphic ventricular tachycardia (VT). METHODS: In our department, 3022 DSE studies were carried out on 2688 patients, aged 54.7 +/- 11.8 years, over a 3.5 year period. Patients with DSE-induced VT were studied by means of coronary angiography and electrophysiological testing, and were followed-up for 17.8 +/- 9.3 months. RESULTS: During DSE, nine patients (0.3%) developed sustained monomorphic VT. Four patients had coronary artery disease, one developed spontaneous right coronary artery (RCA) dissection during DSE, one patient had peripartum cardiomyopathy and the remainder had normal coronary arteries. Logistic regression analysis did not identify clinical parameters such as left ventricular ejection fraction, documentation of an ischaemic response or the presence of non-viable myocardial segments during DSE, that could predict the occurrence of DSE-induced VT. Monomorphic VT was inducible by electrophysiological testing in two patients with CAD and reduced LVEF. During follow-up, only these two patients developed VT. CONCLUSION: Sustained monomorphic VT is a rare complication of DSE, with no predictive value for the identification of patients with coronary artery disease and no prognostic significance in patients with normal coronary arteries. No predictors of its occurrence were identified.

Transcoronary transplantation of autologous mesenchymal stem cells and endothelial progenitors into infarcted human myocardium.

The aim of the study was to investigate whether a combination of mesenchymal stem cells (MSCs) capable of differentiating into cardiac myocytes and endothelial progenitors (EPCs) that mainly promote neoangiogenesis might be able to facilitate tissue repair in myocardial scars. Previous studies have shown that intracoronary transplantation of autologous bone marrow stem cells results in improvement of contractility in infracted areas of human myocardium. Eleven patients with an anteroseptal myocardial infarction (MI) underwent transcoronary transplantation of bone marrow-derived MSCs and EPCs to the infarcted area through the left anterior descending artery. Eleven age- and sex-matched patients served as controls. Wall motion score index was significantly lower at follow-up in the transplantation (P = 0.04) but not in the control group. On stress echocardiography, there was improvement of myocardial contractility in one or more previously nonviable myocardial segments in 5 out of 11 patients (all with recent infarctions) and in none of the controls (P = 0.01). Restoration of uptake of Tc(99m) sestamibi in one or more previously nonviable myocardial scars was seen in 6 out of 11 patients subjected to transplantation and in none of the controls (P = 0.02). Cell transplantation was an independent predictor of improvement of nonviable tissue. Intracoronary transplantation of MSCs and EPCs is feasible, safe, and may contribute to regional regeneration of myocardial tissue early or late following MI.

Comparison of enoxaparin and unfractionated heparin in coronary angioplasty.

INTRODUCTION: Recent studies have shown that enoxaparin may be equally as safe and effective as unfractionated heparin during a coronary angioplasty procedure. The aim of this study was to investigate whether enoxaparin can be used effectively and safely in place of unfractionated heparin in patients undergoing emergency or programmed coronary angioplasty, regardless of the use of platelet glycoprotein IIb/IIIa inhibitors. METHODS: We compared two series of consecutive patients, who received unfractionated heparin (n = 217) or enoxaparin (n = 116) during emergency or programmed angioplasty, regardless of age, weight, renal function and the coadministration of platelet glycoprotein IIb/IIIa inhibitors. In the patients who received enoxaparin the arterial sheaths were removed immediately after the procedure. RESULTS: There were no significant differences between the two groups as regards clinical characteristics or risk factors for coronary artery disease. During a 30-day follow up no major adverse cardiac events were observed (death, myocardial infarction, target vessel revascularisation). Multivariate logistic regression analysis showed no correlation between the anticoagulant used and the occurrence of major cardiac events in the two groups of patients (log odds ratio = -9.46, p = 0.89), after controlling for age, sex, administration of platelet glycoprotein IIb/IIIa inhibitors, number of coronary lesions, number of stents used, clinical picture and risk factors for coronary artery disease. As regards the development of haematoma in the groin, the only significant independent predictive factor for this was the coadministration of platelet glycoprotein IIb/IIIa inhibitors. CONCLUSIONS: The use of enoxaparin in coronary angioplasty is safe, effective and allows faster removal of sheaths and mobilisation of the patient.

Meta-analysis comparing drug-eluting stents with bare metal stents.

We performed a meta-analysis of 10 randomized trials of 5,066 patients with 6 to 12 months of follow-up. The summary risk differences excluded any major differences between the 2 types of stents for death (0.12%, 95% confidence interval [CI] -0.34% to 0.58%, p = 0.60) and overall myocardial infarction (0.04%, 95% CI -0.72% to 0.81%, p = 0.91). There was a modest increase in the risk of Q-wave myocardial infarction with drug-eluting stents (0.36%, 95% CI -0.04% to 0.77%, p = 0.080) but no difference in non-Q-wave myocardial infarction (-0.26%, 95% CI -0.95% to 0.43%, p = 0.47). The trend for increased risk of Q-wave myocardial infarction was seen for paclitaxel and sirolimus stents (risk differences 0.28% and 0.58%, respectively). Drug-eluting stents also had a nonsignificant trend for higher risk of thrombosis (0.29%, 95% CI -0.08% to 0.66%, p = 0.13). We conclude that sirolimus- and paclitaxel-eluting stents are equivalent to bare-metal stents in terms of mortality and overall myocardial infarction risk for the first year of follow-up; the meta-analysis excludes with considerable confidence the presence of large, clinically relevant differences for these outcomes.

Patient dosimetry during coronary interventions: a comprehensive analysis.

BACKGROUND: We performed a detailed analysis of patient radiation during coronary interventions, comparing dose measurements to established dose reference levels, assessing coronary artery doses, and estimating total radiation risk of fatal cancer. METHODS: We prospectively examined 281 patients who were subjected to 307 percutaneous coronary interventions. RESULTS: The mean kerma area product (KAP) per procedure was 82.1 +/- 47.9 Gy x cm2. Corresponding values for fluoroscopy and digital cineangiography were 28.3 +/- 25.5 Gy x cm2 and 53.8 +/- 35.5 Gy x cm2, respectively, and exposure times were 13.1 +/- 6.8 minutes (87%) and 2.0 +/- 1.5 minutes (13%), respectively. The right anterior oblique caudal and left anterior oblique cranial projections accounted for the highest amount of KAP (24.0% and 23.1%, respectively) compared with other projections. The maximum recorded skin-dose was 182 mGy. Performing a representative procedure on a phantom, the effective dose was 14.9 mSv. The mean coronary dose was 61.7 +/- 38.2 mGy, with a highest calculated dose of 220.1 mGy. The third quartile of KAP measurements was 105 Gy x cm2, the 95th percentile was 175 Gy x cm2, and the mean value of KAP measurements was 82 Gy x cm2. The total risk for the development of fatal cancer was calculated as 83 cases for every 100,000 patients subjected to coronary intervention. CONCLUSIONS: A detailed analysis of patient radiation during coronary interventions is presented. Coronary doses and total radiation risk of fatal cancer are also calculated, and a method for establishing dose reference level values is proposed.

Conduction patterns in the cardiac veins: electrophysiologic characteristics of the connections between left atrial and coronary sinus musculature.

INTRODUCTION: Fractionated electrograms and double potentials have been well described within the coronary sinus (CS) in humans. The pattern of circumferential activation in the CS has not been investigated. Furthermore, no data exist on conduction characteristics within the great cardiac vein (GCV) or the middle cardiac vein (MCV). METHODS AND RESULTS: Twenty patients underwent catheter mapping of the CS, the MCV, and the GCV. Anatomical areas were verified by cannulation of the left superior pulmonary vein. The pattern of circumferential muscle activation within the proximal CS was also studied with a circular mapping catheter (Lasso 12 mm). At conventional mapping during sinus rhythm and high right atrial pacing, discrete double potentials or fractionated electrograms were recorded during left, right atrial and CS pacing at the CS ostium, mid-CS, and distal CS-ligament of Marshall area, in 2 (10%), 1 (5%), and 9 (45%) patients, respectively, whereas no patient displayed such signals in the MCV or GCV ( p < 0.001). Proximal CS mapping with the Lasso was accomplished in 10 patients, 7 of whom had no evidence of multicomponent potentials in the CS at conventional mapping. Specific CS potentials dissociated from the atrial electrograms were recorded in all patiens with the use of circumferential mapping. The perimetric distribution of electrograms within the CS suggested an oblique course of conduction across the CS musculature. CONCLUSION: Potentials representing activation of the CS musculature, with an oblique course of conduction across the CS, can be recorded in human CS but not in the GCV or MCV. This is compatible with anatomical observations of sinus venosus musculature covering the CS but not other cardiac veins, and supports the rationale for the role of CS musculature in the generation of atrial arrhythmias.

Medical personnel and patient dosimetry during coronary angiography and intervention.

Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 +/- 9 Gy cm2. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 +/- 30 Gy cm2, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y(-1) for the primary operator, and 0.03-0.04 mSv y(-1) for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

Mortality risk conferred by small elevations of creatine kinase-MB isoenzyme after percutaneous coronary intervention.

OBJECTIVES: The aim of this study was to assess whether small creatine kinase-MB isoenzyme (CK-MB) elevations after percutaneous coronary intervention (PCI) affect the subsequent mortality risk. BACKGROUND: Several studies have evaluated the relationship of CK-MB levels after PCI with the subsequent risk of death. While there is consensus that elevations exceeding 5 times the upper limit of normal increase mortality significantly, there is uncertainty about the exact clinical impact of smaller CK-MB elevations. METHODS: We performed a meta-analysis of seven studies with CK-MB measurements and survival outcomes on 23230 subjects who underwent PCI. Data were combined with random effects models. RESULTS: Mean follow-up was 6 to 34 months per study. By random effects, 19% (95% confidence interval [CI], 16% to 23%) had one- to five-fold CK-MB elevations, while only 6% (95% CI, 5% to 9%) had >5-fold elevations. Compared with subjects with normal CK-MB, there was a dose-response relationship with relative risks for death being 1.5 (95% CI, 1.2 to 1.8, no between-study heterogeneity) with one- to three-fold CK-MB elevations, 1.8 (95% CI, 1.4 to 2.4, no between-study heterogeneity) with three- to five-fold CK-MB elevations, and 3.1 (95% CI, 2.3 to 4.2, borderline between-study heterogeneity) with over five-fold CK-MB elevations (p < 0.001 for all). CONCLUSIONS: Any increase in CK-MB after PCI is associated with a small, but statistically and clinically significant, increase in the subsequent risk of death.

Comparison of effectiveness of carvedilol versus bisoprolol for maintenance of sinus rhythm after cardioversion of persistent atrial fibrillation.

Ninety patients who underwent cardioversion of persistent atrial fibrillation (AF) were randomized to bisoprolol 5 to 10 mg once daily or carvedilol 12.5 to 25 mg twice daily. Using intention-to-treat analysis, 23 patients (46%) in the bisoprolol group and 17 patients (32%) in the carvedilol group relapsed into AF during the 1 year of total follow-up (p = 0.486). Patients treated with carvedilol had a 14% (hazard ratio 0.86) lower risk of relapse of AF compared with patients in the bisoprolol group, although results were statistically insignificant (p = 0.661) after controlling for patient age, gender, baseline heart rate, and left atrial diameter.

Reperfusion in acute myocardial infarction: current concepts.

Myocardial reperfusion is the treatment of choice in acute myocardial infarction. Pharmacological thrombolysis restores coronary artery patency in about two thirds of patients with acute myocardial infarction. However, mechanical reperfusion with primary angioplasty and stenting achieves higher patency rates with less complications, especially in high-risk patients. Adjunctive pharmacotherapy and new device technology may improve the outcome of primary angioplasty. Facilitated angioplasty using a combination of half-dose thrombolysis, platelet glycoprotein IIb/IIIa antagonists, and early intervention, appears to be a promising strategy for the treatment of acute myocardial infarction in the modern era. The efficacy and safety of this approach are currently evaluated in several ongoing trials.