ESC Congress 2007 RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST- ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA - II SUBSTUDY National Registry of Mexican Society of Cardiology Authors : Úrsulo Juárez MD FACC, Carlos Jerjes-Sanchez MD FACC, Eduardo Chuquiure MD, Carlos Martínez MD FACC On Behalf of RENASICA II and Sociedad Mexicana de Cardiología, México City, México.

BACKGROUND-1 Bundle branch block (BBB) early during acute myocardial infarction (AMI) is often considered high risk for mortality Bundle branch block (BBB) early during acute myocardial infarction (AMI) is often considered high risk for mortality In the Fibrinolytic Therapy Trialists’ meta-analysis, patients with BBB at randomization had a 35-day mortality rate of 24% without and 19% with fibrinolytic therapy. The studies included made no distinction between rigth bundle branch block (RBBB) and left bundle branch block (LBBB) and did not specify whether the BBB was new or old In the Fibrinolytic Therapy Trialists’ meta-analysis, patients with BBB at randomization had a 35-day mortality rate of 24% without and 19% with fibrinolytic therapy. The studies included made no distinction between rigth bundle branch block (RBBB) and left bundle branch block (LBBB) and did not specify whether the BBB was new or old Different types of BBB occurring during the initial hours of AMI may have different prognostic implications that are independient of another prognostic factors Different types of BBB occurring during the initial hours of AMI may have different prognostic implications that are independient of another prognostic factors ESC Congress 2007

BACKGROUND-2 Development of new BBB despite prompt fibrinolytic therapy may signify an extensive and ongoing AMI. Some types of BBB may reflect larger infarct territories, indicating that these patients might benefit from more aggressive reperfusion therapy Development of new BBB despite prompt fibrinolytic therapy may signify an extensive and ongoing AMI. Some types of BBB may reflect larger infarct territories, indicating that these patients might benefit from more aggressive reperfusion therapy Until our knowledgment the prognosis of RBBB in patients with acute coronary syndromes is unclear Until our knowledgment the prognosis of RBBB in patients with acute coronary syndromes is unclear Reference : European Heart Journal (2006)27,21-28 ESC Congress 2007

METHODS-1 The RENASICA II Design overview The RENASICA II Design overview Is the largest national registry of ACS recruited 8,098 patients with final diagnosis of ACS ST elevation (STE) or non-ST elevation (NSTE) secundary to ischaemic heart disease and designed to characterize an unbiased and representative population Is the largest national registry of ACS recruited 8,098 patients with final diagnosis of ACS ST elevation (STE) or non-ST elevation (NSTE) secundary to ischaemic heart disease and designed to characterize an unbiased and representative population The patients were enrrolled in 66 primary and tertiary Mexican Hospitals and for quality control criteria af Alpert were used. The hospitals varied in terms of access to on-site cardiac catheterization, number of acute care beds and the type of practice setting with an aim of stlablishing a representative rather than selective study population The patients were enrrolled in 66 primary and tertiary Mexican Hospitals and for quality control criteria af Alpert were used. The hospitals varied in terms of access to on-site cardiac catheterization, number of acute care beds and the type of practice setting with an aim of stlablishing a representative rather than selective study population ESC Congress 2007

METHODS – 2 : Patients with ST acute myocardial infarction (AMI) with LBBB or RBBB were compared in terms of in-hospital outcome and major cardiovascular adverse events (MACE), cardiovascular death, myocardial infarction (MI) and recurrent ischaemia Patients with ST acute myocardial infarction (AMI) with LBBB or RBBB were compared in terms of in-hospital outcome and major cardiovascular adverse events (MACE), cardiovascular death, myocardial infarction (MI) and recurrent ischaemia patients with symptoms precipitated by anemia,hypertension, heart failure, etc were excluded patients with symptoms precipitated by anemia,hypertension, heart failure, etc were excluded BBB was defined as de the QRS duration of 0.12 sec in precence sinus or supraventricular rhythm BBB was defined as de the QRS duration of 0.12 sec in precence sinus or supraventricular rhythm Multivariable Analysis was performed to identify in hospital mortality risk among RBBB and LBBB with MACE Multivariable Analysis was performed to identify in hospital mortality risk among RBBB and LBBB with MACE Odd ratio (OR) and confidence intervals 95% (CI) Odd ratio (OR) and confidence intervals 95% (CI) ESC Congress 2007

Inclusion Criteria Inclusion Criteria INCLUSION (4) 1. lchemic Chest Pain > 20 min 2. ST-E: in BL > 1 mm; Precordial leads > 2 mm 3. QRS duration > 0.12 seg. 4. Complete Register Form – Signed IC 4. Complete Register Form – Signed IC EXCLUTION (1) 1. Non Ischaemic CP precipitated by secundary cause as anemia, heart failure or hypertension 2. Previous BBB 3. Pacemaker rythm 2. Previous BBB 3. Pacemaker rythm RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY ESC Congress 2007

To ensure quality control of registry data the following criteria developed by Alpert were applied in RENASICA II: a)Standarizad definitions and all participants were familiarizad b)Careful hospitals selection c)Hospitals approved registry data collection process d)All collected data were reported e)Original data,electronic submissions were centralized f) A professional statistician analyzed the data g)All data and electronic submissions were examined by the central data management h)Principal investigator and steering committee keep administrative order, adjudicated disagreements and encouraged timely submission of documents and data analysis. ESC Congress 2007 QUALITY

RESULTS 4,555 patients with STE AMI were analyzed in this substudy 4,555 patients with STE AMI were analyzed in this substudy Of them 7% had RBBB and 5% LBBB Of them 7% had RBBB and 5% LBBB There were not statistical differences in both groups among aged, gender baseline characteristics, onset symptoms, ischemic time, AMI location, Killip functional class, ventricular dysfunction, and reperfusion strategies. There were not statistical differences in both groups among aged, gender baseline characteristics, onset symptoms, ischemic time, AMI location, Killip functional class, ventricular dysfunction, and reperfusion strategies. Patients with inferior or anterior STE AMI with RBBB had highest mortality and association with MACE ( OR 1.70, CI 1.19 – 2.42, p< compared to LBBB. Patients with inferior or anterior STE AMI with RBBB had highest mortality and association with MACE ( OR 1.70, CI 1.19 – 2.42, p< compared to LBBB. ESC Congress 2007 RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY

RBBB n= 318 (7%) LBBB n= 227 (5%) Unspeciphic Chest Pain n = 625 (7%) Unspeciphic Chest Pain n = 625 (7%) UA / Non ST AMI* n = 3,445 (40%) UA / Non ST AMI* n = 3,445 (40%) STE AMI** n = 4,555 (53%) n = 8,098 Patients with ACS * UA/Non ST AMI = Unstable Angina No ST elevation acute myocardial infarction ** STE AMI = ST elevation acute myocardial infarction RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY ESC Congress 2007

RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY ACS-AMI-ST ELEVATION RENASICA – II REGISTRY n = 4,555 STEMI RIGTH BUNDLE BRANCH BLOCK N = 318 ( 7% ) In Hospital Outcome – Major Cardiovascular Adverse Events – Cardiovascular Death Recurrent ischemia – Re AMI Multivariable Analysis to In Hospital Mortality Risk among RBBB and LBBB with MACE Odd Ratio (OR) and Confidence Intervals 95% LEFT BUNDLE BRANCH BLOCK N = 227 ( 5% ) BBB n = 545 patients ESC Congress 2007

Baseline Characteristics-1 Baseline Characteristics RBBB (n=318) 35 Previous AMI (%) 59 Hypertension (%) 26 Hyperlipidemia (%) 66 Current/former smoker (%) 47 Diabetes (%) 71 Men (%) 67.3 Age-years- median LBBB (n=227) Characteristic all p = NS ESC Congress 2007

RBBB (n=318) K Killip I (n =) II II III III IV IV 2316 AMI location (%) AnteriorInferior LBBB (n=227) Characteristic All p = NS Baseline Characteristics-2 Baseline Characteristics-2 ESC Congress 2007

TREATMENT TREATMENT RBBB (n=318) 59 IECA/ARB (%) 89 ASA (%) 51 Beta Bloq.(%) LBBB (n=227) Medication 1413 Statins (%) all p = NS Reperfusion Strategy Lytic (%) Primary PTCA (%) Clopidogrel (%) ESC Congress 2007

Outcomes in Hospital Comparison in both BBB and MACE P value = ns % LBBB RBBB * ESC Congress

LBBB RBBB 3 rd degree AV block ST Depresion in > 3 ECG leads (OR 1.7, CI 1.1 – 2.5) (OR 1.7, CI 1.1 – 2.4) (OR 2.4, 95% CI 1.9 –3.1) findings ECG IN HOSPITAL MORTALITY PREDICTORS IN STEMI A SUBSTUDY OF RENASICA II logistic regresion in mortality predictors ESC Congress 2007

Clinical Implications The higher mortality and higher incidence of RBBB seen in patients with anterior AMI may be axplained by: The higher mortality and higher incidence of RBBB seen in patients with anterior AMI may be axplained by: Septal ischaemia from a more proximal left descending artery occlusion (before the large septal branch) Septal ischaemia from a more proximal left descending artery occlusion (before the large septal branch) The course of the rigth bundle branch traversing the septum towards the apex. The course of the rigth bundle branch traversing the septum towards the apex. Limitations As in all clinical trials, a selection bias could have occurred in RENASICA II resulting in under-representation of very high risk patients (including those with RBBB accompanying anterior AMI) in the trial cohort. As in all clinical trials, a selection bias could have occurred in RENASICA II resulting in under-representation of very high risk patients (including those with RBBB accompanying anterior AMI) in the trial cohort. ESC Congress 2007

Conclusion The RBBB accompanying anterior or inferior AMI at presentation was an independient predictor of high in hospital mortality. These electrocardiographics features should be considered in risk stratification to identify high- risk patients ESC Congress 2007 RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY RIGTH BUNDLE BRANCH BLOCK AS RISK MARKER OF IN HOSPITAL MORTALITY IN ST-ELEVATION ACUTE MYOCARDIAL INFARCTION. A RENASICA- II SUBSTUDY