José M. García-Ruiz

Effect of Early Metoprolol on Infarct Size in ST-Segment–Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention The Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction (METOCARD-CNIC) Trial

Background —The effect of β-blockers on infarct size when used in conjunction with primary percutaneous coronary intervention (PCI) is unknown. We hypothesize that metoprolol reduces infarct size when administered early (intravenously [i.v.] before reperfusion). Methods and Results —Patients with Killip-class ≤II anterior ST-segment elevation myocardial infarction (STEMI) undergoing PCI within 6 hours of symptoms onset were randomized to receive i.v. metoprolol (n=131) or not (control, n=139) pre-reperfusion. All patients without contraindications received oral metoprolol within 24 hours. The pre-defined primary endpoint was infarct size on magnetic resonance imaging (MRI) performed 5-7 days after STEMI. MRI was performed in 220 patients (81%). Mean (±SD) infarct size by MRI was smaller after i.v. metoprolol compared to control (25.6±15.3 vs. 32.0±22.2 grams; adjusted difference, -6.52; 95% confidence interval [CI], -11.39 to -1.78; P=0.012). In patients with pre-PCI TIMI flow grade 0/1, the adjusted treatment difference in infarct size was -8.02; 95% CI, -13.01 to -3.02; P=0.0029. Infarct size estimated by peak and area under the curve creatine-kinase release was measured in all study population and was significantly reduced by i.v. metoprolol. Left ventricular ejection fraction was higher in the i.v. metoprolol group (adjusted difference 2.67%; 95% CI, 0.09% to 5.21%; P=0.045). The composite of death, malignant ventricular arrhythmia, cardiogenic shock, atrioventricular block and reinfarction at 24 hours in the i.v. metoprolol and control groups respectively was 7.1% vs. 12.3%, p=0.21. Conclusions —In patients with anterior Killip-class ≤II STEMI undergoing primary PCI, early i.v. metoprolol before reperfusion reduced infarct size and increased LVEF with no excess of adverse events during the first 24 hours after STEMI. Clinical Trial Registration Information —ClinicalTrials.gov. Identifier: [NCT01311700][1] & EUDRACT Number 2010-019939-35. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01311700&atom=%2Fcirculationaha%2Fearly%2F2013%2F09%2F03%2FCIRCULATIONAHA.113.003653.atomBackground— The effect of &bgr;-blockers on infarct size when used in conjunction with primary percutaneous coronary intervention is unknown. We hypothesize that metoprolol reduces infarct size when administered early (intravenously before reperfusion). Methods and Results— Patients with Killip class II or less anterior ST-segment–elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention within 6 hours of symptoms onset were randomized to receive intravenous metoprolol (n=131) or not (control, n=139) before reperfusion. All patients without contraindications received oral metoprolol within 24 hours. The predefined primary end point was infarct size on magnetic resonance imaging performed 5 to 7 days after STEMI. Magnetic resonance imaging was performed in 220 patients (81%). Mean±SD infarct size by magnetic resonance imaging was smaller after intravenous metoprolol compared with control (25.6±15.3 versus 32.0±22.2 g; adjusted difference, −6.52; 95% confidence interval, −11.39 to −1.78; P=0.012). In patients with pre–percutaneous coronary intervention Thrombolysis in Myocardial Infarction grade 0 to 1 flow, the adjusted treatment difference in infarct size was −8.13 (95% confidence interval, −13.10 to −3.16; P=0.0024). Infarct size estimated by peak and area under the curve creatine kinase release was measured in all study populations and was significantly reduced by intravenous metoprolol. Left ventricular ejection fraction was higher in the intravenous metoprolol group (adjusted difference, 2.67%; 95% confidence interval, 0.09–5.21; P=0.045). The composite of death, malignant ventricular arrhythmia, cardiogenic shock, atrioventricular block, and reinfarction at 24 hours in the intravenous metoprolol and control groups was 7.1% and 12.3%, respectively (P=0.21). Conclusions— In patients with anterior Killip class II or less ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention, early intravenous metoprolol before reperfusion reduced infarct size and increased left ventricular ejection fraction with no excess of adverse events during the first 24 hours after STEMI. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01311700. EUDRACT number: 2010-019939-35.

Myocardial Edema After Ischemia/Reperfusion Is Not Stable and Follows a Bimodal Pattern: Imaging and Histological Tissue Characterization

BACKGROUND It is widely accepted that edema occurs early in the ischemic zone and persists in stable form for at least 1 week after myocardial ischemia/reperfusion. However, there are no longitudinal studies covering from very early (minutes) to late (1 week) reperfusion stages confirming this phenomenon. OBJECTIVES This study sought to perform a comprehensive longitudinal imaging and histological characterization of the edematous reaction after experimental myocardial ischemia/reperfusion. METHODS The study population consisted of 25 instrumented Large-White pigs (30 kg to 40 kg). Closed-chest 40-min ischemia/reperfusion was performed in 20 pigs, which were sacrificed at 120 min (n = 5), 24 h (n = 5), 4 days (n = 5), and 7 days (n = 5) after reperfusion and processed for histological quantification of myocardial water content. Cardiac magnetic resonance (CMR) scans with T2-weighted short-tau inversion recovery and T2-mapping sequences were performed at every follow-up stage until sacrifice. Five additional pigs sacrificed after baseline CMR served as controls. RESULTS In all pigs, reperfusion was associated with a significant increase in T2 relaxation times in the ischemic region. On 24-h CMR, ischemic myocardium T2 times returned to normal values (similar to those seen pre-infarction). Thereafter, ischemic myocardium-T2 times in CMR performed on days 4 and 7 after reperfusion progressively and systematically increased. On day 7 CMR, T2 relaxation times were as high as those observed at reperfusion. Myocardial water content analysis in the ischemic region showed a parallel bimodal pattern: 2 high water content peaks at reperfusion and at day 7, and a significant decrease at 24 h. CONCLUSIONS Contrary to the accepted view, myocardial edema during the first week after ischemia/reperfusion follows a bimodal pattern. The initial wave appears abruptly upon reperfusion and dissipates at 24 h. Conversely, the deferred wave of edema appears progressively days after ischemia/reperfusion and is maximal around day 7 after reperfusion.

Long-term benefit of early pre-reperfusion metoprolol administration in patients with acute myocardial infarction: results from the METOCARD-CNIC trial (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction)

OBJECTIVES The goal of this trial was to study the long-term effects of intravenous (IV) metoprolol administration before reperfusion on left ventricular (LV) function and clinical events. BACKGROUND Early IV metoprolol during ST-segment elevation myocardial infarction (STEMI) has been shown to reduce infarct size when used in conjunction with primary percutaneous coronary intervention (pPCI). METHODS The METOCARD-CNIC (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction) trial recruited 270 patients with Killip class ≤II anterior STEMI presenting early after symptom onset (<6 h) and randomized them to pre-reperfusion IV metoprolol or control group. Long-term magnetic resonance imaging (MRI) was performed on 202 patients (101 per group) 6 months after STEMI. Patients had a minimal 12-month clinical follow-up. RESULTS Left ventricular ejection fraction (LVEF) at the 6 months MRI was higher after IV metoprolol (48.7 ± 9.9% vs. 45.0 ± 11.7% in control subjects; adjusted treatment effect 3.49%; 95% confidence interval [CI]: 0.44% to 6.55%; p = 0.025). The occurrence of severely depressed LVEF (≤35%) at 6 months was significantly lower in patients treated with IV metoprolol (11% vs. 27%, p = 0.006). The proportion of patients fulfilling Class I indications for an implantable cardioverter-defibrillator (ICD) was significantly lower in the IV metoprolol group (7% vs. 20%, p = 0.012). At a median follow-up of 2 years, occurrence of the pre-specified composite of death, heart failure admission, reinfarction, and malignant arrhythmias was 10.8% in the IV metoprolol group versus 18.3% in the control group, adjusted hazard ratio (HR): 0.55; 95% CI: 0.26 to 1.04; p = 0.065. Heart failure admission was significantly lower in the IV metoprolol group (HR: 0.32; 95% CI: 0.015 to 0.95; p = 0.046). CONCLUSIONS In patients with anterior Killip class ≤II STEMI undergoing pPCI, early IV metoprolol before reperfusion resulted in higher long-term LVEF, reduced incidence of severe LV systolic dysfunction and ICD indications, and fewer heart failure admissions. (Effect of METOprolol in CARDioproteCtioN During an Acute Myocardial InfarCtion. The METOCARD-CNIC Trial; NCT01311700).

Long term benefit of early pre-reperfusion metoprolol administration in patients with acute myocardial infarction: results from the METOCARD-CNIC trial.

OBJECTIVES The goal of this trial was to study the long-term effects of intravenous (IV) metoprolol administration before reperfusion on left ventricular (LV) function and clinical events. BACKGROUND Early IV metoprolol during ST-segment elevation myocardial infarction (STEMI) has been shown to reduce infarct size when used in conjunction with primary percutaneous coronary intervention (pPCI). METHODS The METOCARD-CNIC (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction) trial recruited 270 patients with Killip class ≤II anterior STEMI presenting early after symptom onset (<6 h) and randomized them to pre-reperfusion IV metoprolol or control group. Long-term magnetic resonance imaging (MRI) was performed on 202 patients (101 per group) 6 months after STEMI. Patients had a minimal 12-month clinical follow-up. RESULTS Left ventricular ejection fraction (LVEF) at the 6 months MRI was higher after IV metoprolol (48.7 ± 9.9% vs. 45.0 ± 11.7% in control subjects; adjusted treatment effect 3.49%; 95% confidence interval [CI]: 0.44% to 6.55%; p = 0.025). The occurrence of severely depressed LVEF (≤35%) at 6 months was significantly lower in patients treated with IV metoprolol (11% vs. 27%, p = 0.006). The proportion of patients fulfilling Class I indications for an implantable cardioverter-defibrillator (ICD) was significantly lower in the IV metoprolol group (7% vs. 20%, p = 0.012). At a median follow-up of 2 years, occurrence of the pre-specified composite of death, heart failure admission, reinfarction, and malignant arrhythmias was 10.8% in the IV metoprolol group versus 18.3% in the control group, adjusted hazard ratio (HR): 0.55; 95% CI: 0.26 to 1.04; p = 0.065. Heart failure admission was significantly lower in the IV metoprolol group (HR: 0.32; 95% CI: 0.015 to 0.95; p = 0.046). CONCLUSIONS In patients with anterior Killip class ≤II STEMI undergoing pPCI, early IV metoprolol before reperfusion resulted in higher long-term LVEF, reduced incidence of severe LV systolic dysfunction and ICD indications, and fewer heart failure admissions. (Effect of METOprolol in CARDioproteCtioN During an Acute Myocardial InfarCtion. The METOCARD-CNIC Trial; NCT01311700).

Prevalence and outcome of newly detected diabetes in patients who undergo percutaneous coronary intervention

AIMS The beneficial effect of specific measures in patients with newly detected diabetes during percutaneous coronary intervention (PCI) has been poorly studied. Here, we determined the prevalence of newly detected diabetes in a cohort of patients who underwent PCI and analysed their clinical outcome. METHODS AND RESULTS A prospective study included patients without previous diagnosis of diabetes that were referred for PCI between November 2005 and May 2006. Major cardiac events were registered after admission and during 12 months of follow-up, and oral glucose tolerance was tested at 15 days after hospital discharge. Six hundred and sixty-two consecutive patients were referred to our hospital for PCI. The distribution of the glycometabolic state of the entire population was (95% CI): known diabetes 28.8% (25.2-32.6), newly detected diabetes 16.2% (13.1-19.8), impaired glucose tolerance 24.5% (20.8-28.5), impaired fasting glucose 1% (0.4-2.4), and normal glucose regulation 29.5% (25.5-33.7). In a multivariable analysis, the presence of newly detected diabetes was not an independent predictor of cardiac events after 1 year of follow-up. CONCLUSION The prevalence of diabetes in patients who underwent PCI was very high (45%), 35% of which was patients with newly detected diabetes. In our series newly detected diabetes was not an independent predictor of outcome at 12 months. Nevertheless, this finding requires independent confirmation in other series to draw general conclusions on the whole spectrum of percutaneous interventions.

Association of Myocardial T1-Mapping CMR With Hemodynamics and RV Performance in Pulmonary Hypertension

Early detection of right ventricular (RV) involvement in chronic pulmonary hypertension (PH) is essential due to prognostic implications. T1 mapping by cardiac magnetic resonance (CMR) has emerged as a noninvasive technique for extracellular volume fraction (ECV) quantification. We assessed the association of myocardial native T1 time and equilibrium contrast ECV (Eq-ECV) at the RV insertion points with pulmonary hemodynamics and RV performance in an experimental model of chronic PH. Right heart catheterization followed by immediate CMR was performed on 38 pigs with chronic PH (generated by surgical pulmonary vein banding) and 6 sham-operated controls. Native T1 and Eq-ECV values at the RV insertion points were both significantly higher in banded animals than in controls and showed significant correlation with pulmonary hemodynamics, RV arterial coupling, and RV performance. Eq-ECV values also increased before overt RV systolic dysfunction, offering potential for the early detection of myocardial involvement in chronic PH.

Exercise Triggers ARVC Phenotype in Mice Expressing a Disease-Causing Mutated Version of Human Plakophilin-2

BACKGROUND Exercise has been proposed as a trigger for arrhythmogenic right ventricular cardiomyopathy (ARVC) phenotype manifestation; however, research is hampered by the limited availability of animal models in which disease-associated mutations can be tested. OBJECTIVES This study evaluated the impact of exercise on ARVC cardiac manifestations in mice after adeno-associated virus (AAV)-mediated gene delivery of mutant human PKP2, which encodes the desmosomal protein plakophilin-2. METHODS We developed a new model of cardiac tissue-specific transgenic-like mice on the basis of AAV gene transfer to test the potential of a combination of a human PKP2 mutation and endurance training to trigger an ARVC-like phenotype. RESULTS Stable cardiac expression of mutant PKP2 (c.2203C>T), encoding the R735X mutant protein, was achieved 4 weeks after a single AAV9-R735X intravenous injection. High-field cardiac magnetic resonance over a 10-month postinfection follow-up did not detect an overt right ventricular (RV) phenotype in nonexercised (sedentary) mice. In contrast, endurance exercise training (initiated 2 weeks after AAV9-R735X injection) resulted in clear RV dysfunction that resembled the ARVC phenotype (impaired global RV systolic function and RV regional wall motion abnormalities on cardiac magnetic resonance). At the histological level, RV samples from endurance-trained R735X-infected mice displayed connexin 43 delocalization at intercardiomyocyte gap junctions, a change not observed in sedentary mice. CONCLUSIONS The introduction of the PKP2 R735X mutation into mice resulted in an exercise-dependent ARVC phenotype. The R735X mutation appears to function as a dominant-negative variant. This novel system for AAV-mediated introduction of a mutation into wild-type mice has broad potential for study of the implication of diverse mutations in complex cardiomyopathies.

Noninvasive monitoring of serial changes in pulmonary vascular resistance and acute vasodilator testing using cardiac magnetic resonance.

OBJECTIVES The study sought to evaluate the ability of cardiac magnetic resonance (CMR) to monitor acute and long-term changes in pulmonary vascular resistance (PVR) noninvasively. BACKGROUND PVR monitoring during the follow-up of patients with pulmonary hypertension (PH) and the response to vasodilator testing require invasive right heart catheterization. METHODS An experimental study in pigs was designed to evaluate the ability of CMR to monitor: 1) an acute increase in PVR generated by acute pulmonary embolization (n = 10); 2) serial changes in PVR in chronic PH (n = 22); and 3) changes in PVR during vasodilator testing in chronic PH (n = 10). CMR studies were performed with simultaneous hemodynamic assessment using a CMR-compatible Swan-Ganz catheter. Average flow velocity in the main pulmonary artery (PA) was quantified with phase contrast imaging. Pearson correlation and mixed model analysis were used to correlate changes in PVR with changes in CMR-quantified PA velocity. Additionally, PVR was estimated from CMR data (PA velocity and right ventricular ejection fraction) using a formula previously validated. RESULTS Changes in PA velocity strongly and inversely correlated with acute increases in PVR induced by pulmonary embolization (r = -0.92), serial PVR fluctuations in chronic PH (r = -0.89), and acute reductions during vasodilator testing (r = -0.89, p ≤ 0.01 for all). CMR-estimated PVR showed adequate agreement with invasive PVR (mean bias -1.1 Wood units,; 95% confidence interval: -5.9 to 3.7) and changes in both indices correlated strongly (r = 0.86, p < 0.01). CONCLUSIONS CMR allows for noninvasive monitoring of acute and chronic changes in PVR in PH. This capability may be valuable in the evaluation and follow-up of patients with PH.

Real Incidence of Diabetes Mellitus in a Coronary Disease Population

The high prevalence of unknown diabetes mellitus (DM) in patients with coronary disease and that the oral glucose tolerance test (OGTT) is the best diagnostic method in this context are well known. However, data about the incidence of DM in this population have not been well described. In the present study, we sought to determine the actual incidence of new-onset DM in patients with coronary disease using the OGTT. Our secondary objective was to validate a predictive model. We studied a series of 338 patients with coronary disease without known DM using the OGTT. After the OGTT, the patients were reclassified as normoglycemic, prediabetic, and unknown DM, according to the American Diabetes Association 2010 criteria. After 3 years of follow-up, the patients without DM were again reassessed using the OGTT. We then built a predictive model using the multivariate logistic regression method and validated it using the leave-one-out method. The final sample was 191 patients. The mean follow-up was 3.13 years. The overall incidence of DM was 43.6 cases/1,000 person-years (95% confidence interval [CI] 26.8 to 60.4). The incidence was significantly different between the initially normoglycemic patients (11.5%, 95% CI 2.3% to 31.8%) and the prediabetic patients (70.5%, 95% CI 42.7% to 98.3%; p <0.001). A risk model that included the glucose level 2 hours after challenge, glycosylated hemoglobin and triglyceride levels, and presence of noncoronary vascular disease showed good predictive capacity for incident DM (area under the curve 0.882, 95% CI 0.819 to 0.946; p <0.0001). In conclusion, the real incidence of new DM is very high in the coronary population, especially in those with prediabetes. It is necessary to use the OGTT for diagnosis, but we can optimize its indication using a risk model.

Neutrophil stunning by metoprolol reduces infarct size

The β1-adrenergic-receptor (ADRB1) antagonist metoprolol reduces infarct size in acute myocardial infarction (AMI) patients. The prevailing view has been that metoprolol acts mainly on cardiomyocytes. Here, we demonstrate that metoprolol reduces reperfusion injury by targeting the haematopoietic compartment. Metoprolol inhibits neutrophil migration in an ADRB1-dependent manner. Metoprolol acts during early phases of neutrophil recruitment by impairing structural and functional rearrangements needed for productive engagement of circulating platelets, resulting in erratic intravascular dynamics and blunted inflammation. Depletion of neutrophils, ablation of Adrb1 in haematopoietic cells, or blockade of PSGL-1, the receptor involved in neutrophil–platelet interactions, fully abrogated metoprolols infarct-limiting effects. The association between neutrophil count and microvascular obstruction is abolished in metoprolol-treated AMI patients. Metoprolol inhibits neutrophil–platelet interactions in AMI patients by targeting neutrophils. Identification of the relevant role of ADRB1 in haematopoietic cells during acute injury and the protective role upon its modulation offers potential for developing new therapeutic strategies.