Author + information
- Received July 6, 2015
- Revision received August 12, 2015
- Accepted August 17, 2015
- Published online December 1, 2015.
- Prakash Harikrishnan, MD∗,
- Tanush Gupta, MD∗,
- Chandrasekar Palaniswamy, MD†,
- Dhaval Kolte, MD, PhD‡,
- Sahil Khera, MD∗,
- Marjan Mujib, MD, MPH∗,
- Wilbert S. Aronow, MD∗∗ (, )
- Chul Ahn, PhD§,
- Sachin Sule, MD∗,
- Diwakar Jain, MD∗,
- Ali Ahmed, MD, MPH‖,
- Howard A. Cooper, MD∗,
- Jason Jacobson, MD∗,
- Sei Iwai, MD∗,
- William H. Frishman, MD∗,
- Deepak L. Bhatt, MD, MPH¶,
- Gregg C. Fonarow, MD# and
- Julio A. Panza, MD∗
- ∗New York Medical College, Valhalla, New York
- †Icahn School of Medicine at Mount Sinai Hospital, New York, New York
- ‡Brown University/Rhode Island Hospital, Providence, Rhode Island
- §Department of Clinical Sciences and Biostatistics, University of Texas Southwestern Medical Center, Dallas, Texas
- ‖VA Medical Center, Washington, DC
- ¶Brigham and Women’s Hospital Heart & Vascular Center and Harvard Medical School, Boston, Massachusetts
- #David-Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, California
- ↵∗Reprint requests and correspondence:
Dr. Wilbert S. Aronow, Macy Pavilion, Room 148, New York Medical College, 100 Woods Road, Valhalla, New York 10595.
Objectives The purpose of this study was to determine the association of complete heart block (CHB) with outcomes and to examine temporal trends in the incidence and outcomes of CHB complicating ST-segment elevation myocardial infarction (STEMI).
Background There are limited data available on the incidence and outcomes of CHB in STEMI patients who undergo contemporary management.
Methods We used the 2003 to 2012 National Inpatient Sample databases to identify all patients age ≥18 years hospitalized with STEMI. Patients with a concomitant diagnosis of CHB were then identified. Multivariable logistic regression was used to analyze the association of CHB with outcomes and to examine the temporal trends in incidence and outcomes of CHB complicating STEMI.
Results Of 2,273,853 patients with STEMI, 49,882 (2.2%) had CHB. The incidence of CHB increased from 2.1% in 2003 to 2.3% in 2012 (adjusted odds ratio [OR] per year: 1.02; 95% confidence interval [CI]: 1.02 to 1.03). STEMI patients with CHB had higher in-hospital mortality than those without CHB (20.4% vs. 8.7%; adjusted OR: 2.47; 95% CI: 2.41 to 2.53). The higher mortality associated with CHB was independent of the location of STEMI; however, the magnitude of this association was greatest in patients with anterior STEMI. In patients with CHB complicating STEMI, although permanent pacemaker implantation rates declined (adjusted OR per year: 0.96; 95% CI: 0.95 to 0.97), in-hospital mortality remained unchanged during the study period (adjusted OR per year: 1.00; 95% CI: 0.99 to 1.01).
Conclusions The incidence of CHB complicating STEMI has increased slightly over the last decade, although the absolute incidence remains quite low. CHB remains associated with higher in-hospital mortality in STEMI patients even in the current era of prompt reperfusion therapy. In patients with CHB complicating STEMI, there was no change in risk-adjusted in-hospital mortality during the study period.
Complete heart block (CHB) is a relatively frequent complication in patients hospitalized with acute myocardial infarction (AMI) (1). Previous studies have reported the overall incidence of CHB in patients with AMI to be between 3% and 13% depending on the type and anatomical location of the AMI being investigated (2–8). Patients who develop CHB in the setting of AMI have a 3- to 5-fold increase in in-hospital mortality compared with those without CHB (6–8). However, most of these reports are from the pre-thrombolytic and thrombolytic era in the 1980s and 1990s, before the widespread use of percutaneous coronary intervention (PCI) and the advent of modern adjunctive medical therapies. Data on the incidence and outcomes of CHB in patients with ST-segment elevation myocardial infarction (STEMI) in the contemporary PCI era are limited. Hence, the primary objective of this study was to examine the association of CHB with in-hospital outcomes in patients hospitalized with STEMI and to examine the temporal trends in the incidence and outcomes of CHB complicating STEMI using the National Inpatient Sample (NIS) databases from 2003 to 2012. It has been previously shown that inferior STEMI is associated with a higher incidence of CHB (6,9); therefore, we also conducted subgroup analysis after stratifying patients by STEMI location to those with anterior, inferior, or other STEMI.
Data were obtained from the 2003 to 2012 NIS databases. The NIS, developed as a part of the Healthcare Cost and Utilization Project, is the largest publicly available all-payer inpatient care database in the United States, and is sponsored by the Agency for Healthcare Research and Quality (10). The NIS includes data from all nonfederal, short-term, general, and other specialty hospitals in the United States (excluding rehabilitation and long-term acute care hospitals) in the form of de-identified patient information containing demographics, discharge diagnoses, comorbidities, procedures, outcomes, and hospitalization costs. All the states that participate in Healthcare Cost and Utilization Project (n = 44 in 2012) provide data to the NIS, covering >95% of the U.S. population. The design of the NIS changed during our study. Between 2003 and 2011, the NIS included data on all inpatient discharges from a random 20% sample of community hospitals in the United States. However, in 2012, the database was redesigned to include data from a 20% sample of discharges from all participating hospitals. The new design of the NIS reduces the margin of error for estimates and delivers more stable and precise estimations. For patient-level trend analysis, a new set of weights called trend weights are provided for the 2012 data, as well as for the data from previous years (11). The New York Medical College Institutional Review Board deemed this study exempt because Healthcare Cost and Utilization Project-NIS is a publicly available database containing de-identified patient information.
We used the International Classification of Diseases-Ninth Edition-Clinical Modification (ICD-9-CM) diagnosis codes 410.01, 410.11, 410.21, 410.31, 410.41, 410.51, 410.61, 410.81, and 410.91 to identify all patients ≥18 years of age hospitalized with the principal diagnosis of STEMI. We chose the principal diagnosis because it is considered the primary reason for hospitalization. This approach has been used by previous studies using the NIS database to accurately identify patients with STEMI (12,13). Patients with pacemakers (ICD-9-CM code V45.01) or implantable cardioverter-defibrillators (ICD-9-CM code V45.02) were excluded. Patients with CHB were then identified using ICD-9-CM code 426.0.
We studied the temporal trends in incidence of CHB in the overall cohort of patients with STEMI. All-cause in-hospital mortality, which was defined as “died” during the hospitalization encounter in the NIS database, was the primary outcome of interest. Use of temporary transvenous pacing (TTVP), permanent pacemaker (PPM) implantation (not including patients who underwent implantable cardioverter-defibrillator placement), and average length of stay (LOS) were used as secondary outcomes.
Patient and hospital characteristics
Baseline patient characteristics included demographics (age, sex, race), weekday versus weekend admission, primary payer status, 29 Elixhauser comorbidities as defined by the Agency for Healthcare Research and Quality (14,15), and other clinically relevant comorbidities (smoking, dyslipidemia, previous MI, previous PCI, or previous coronary artery bypass grafting [CABG]). Online Table 1 lists the ICD-9-CM and Clinical Classification Software codes used to identify comorbidities and procedures. Hospital characteristics that were used included the hospital region (Northeast, Midwest, South, or West), bed size (small, medium, or large), location (urban or rural), and teaching status. ICD-9-CM procedure codes were used to identify patients who underwent thrombolysis, PCI, or CABG.
Weighted estimates were calculated by applying trend weights to the unweighted discharge data.
We initially compared the baseline patient and hospital characteristics between STEMI patients with and without CHB using the Pearson chi-square test for categorical variables and 1-way analysis of variance for continuous variables to identify significant univariate associations. Multivariable logistic regression was used to compare in-hospital mortality in STEMI patients with and without CHB in the overall cohort of patients with STEMI and after stratifying patients by treatment strategy (thrombolysis, PCI, CABG, or no reperfusion) and by STEMI location (anterior, inferior, or other STEMI). Variables included in the regression model were demographics, hospital characteristics, all Elixhauser, and other clinically relevant comorbidities. Race/ethnicity data were not available for 23.1% of the study population, and are therefore reported in the descriptive statistics but not included in the regression models. Because of the abstracted nature of our data, we were unable to determine whether CHB preceded or occurred after reperfusion therapy. Therefore, we did not adjust for the use of reperfusion in our regression models. Multivariable linear regression after log transformation of the dependent variable was used to compare average LOS between STEMI patients with and without CHB.
For trend analyses, we used the Cochrane-Armitage test for categorical variables and linear regression for continuous variables. Multivariable logistic regression adjusting for all of the previously mentioned variables was used to assess whether the incidence of CHB in STEMI, use of TTVP or PPM for CHB, and in-hospital mortality in STEMI patients with CHB changed over time. Initially, to obtain unadjusted and adjusted odds ratios (ORs) per year for the temporal trends, we entered our independent variable (calendar year) as a continuous variable in the regression models. Then, to measure if there was a temporal variability from year to year, we also evaluated calendar year as a categorical variable, with 2003 as the reference year. Multivariable linear regression after log transformation of the dependent variable was used to analyze the temporal trends in average LOS. We further explored temporal trends in the incidence and outcomes of CHB in subgroups of patients with anterior, inferior, or other STEMI. We also compared the incidence and outcomes of CHB between patients with anterior STEMI, inferior STEMI, and other STEMI.
SPSS Statistics 20.0 (IBM Corp., Armonk, New York) was used to perform the statistical analysis. All p values were 2 sided with a significance threshold of <0.05. Categorical variables are expressed as percentages and continuous variables as mean ± SD. ORs and 95% confidence intervals (CIs) are used to report the results of logistic regression.
Incidence of CHB in patients with STEMI
A total of 2,273,853 patients aged ≥18 years were hospitalized with STEMI from 2003 to 2012. Overall, CHB was present in 49,882 (2.2%) of the STEMI patients. Compared with STEMI patients without CHB, those with CHB were more likely to be older, women, and have more underlying comorbidities (Table 1, Online Table 2). The incidence of CHB was higher in patients with inferior STEMI compared with those with anterior STEMI (3.8% vs. 0.9%; unadjusted OR: 4.15; 95% CI: 4.04 to 4.26; adjusted OR: 4.83; 95% CI: 4.71 to 4.96; p < 0.001) or other STEMI (3.8% vs. 1%; unadjusted OR: 3.90; 95% CI: 3.79 to 4.02; adjusted OR: 5.05; 95% CI: 4.90 to 5.21; p < 0.001). Trend analysis showed a slight but statistically significant increase in the incidence of CHB complicating STEMI from 2.1% in 2003 to 2.3% in 2012 (unadjusted OR per year: 1.02; 95% CI: 1.01 to 1.02; adjusted OR per year: 1.02; 95% CI: 1.02 to 1.03; ptrend <0.001) (Figure 1A). Similar temporal trends in increasing incidence of CHB were seen in subgroups of patients with anterior, inferior, and other STEMI (Figure 1B, Online Table 3). Online Table 4 lists the changes in baseline characteristics from 2003 to 2012 in patients with CHB and STEMI. There was a temporal increase in the prevalence of most comorbid conditions.
In the overall cohort of STEMI patients, thrombolysis was performed in 3.9% of the patients, PCI: in 56.7%, and CABG in 6.5%, whereas 32.8% of the patients did not undergo reperfusion therapy. From 2003 to 2012, the use of PCI increased (from 43.6% to 70.8%, ptrend <0.001), whereas the use of other forms of reperfusion (thrombolysis, from 5.3% to 4.6%, ptrend <0.001, and CABG, from 8.1% to 4.4%, ptrend <0.001) decreased. Overall, the proportion of STEMI patients who did not undergo reperfusion decreased from 43.0% in 2003 to 20.1% in 2012 (ptrend <0.001). Compared with patients without CHB, STEMI patients with CHB were more likely to undergo reperfusion therapy (74.2% vs. 67.0%; adjusted OR: 1.50; 95% CI: 1.47 to 1.54, p < 0.001). Specifically, patients with CHB were more likely to undergo PCI (64.5% vs. 56.5%; adjusted OR: 1.56; 95% CI: 1.53 to 1.60; p < 0.001), less likely to undergo CABG (5.7% vs. 6.5%; adjusted OR: 0.76; 95% CI: 0.73 to 0.79; p < 0.001), and had a similar likelihood of undergoing thrombolysis (4.0% vs. 3.9%; adjusted OR: 1.01; 95% CI: 0.97 to 1.06; p = 0.67).
Temporary and permanent pacemaker use in patients with CHB complicating STEMI
In the overall cohort of STEMI patients with CHB, TTVP was used in 31.8% of the patients. TTVP use rates were lower in patients with anterior STEMI (31.0%) or other STEMI (28.4%) compared with those with inferior STEMI (32.5%). Of STEMI patients with CHB who underwent TTVP implantation and survived hospitalization, the proportion of patients who went on to receive PPM was 15.6%; this proportion was higher in patients with anterior STEMI or other STEMI compared with those with inferior STEMI. Similarly, the overall PPM use rates for CHB were higher in patients with anterior STEMI (18.2%) or other STEMI (20.8%) compared with patients with inferior STEMI (11.5%) (Table 2). Overall, in patients with CHB complicating STEMI, the TTVP use rates remained unchanged during the study period (from 30.9% in 2003 to 32.9% in 2012; adjusted OR per year: 1.00; 95% CI: 0.99 to 1.01, ptrend = 0.91) (Figure 2, Online Table 5), whereas PPM use rates declined (from 16.6% in 2003 to 10.1% in 2012; adjusted OR per year: 0.96; 95% CI: 0.95 to 0.97; ptrend <0.001) (Figure 3, Online Table 5).
The overall in-hospital mortality in STEMI patients with CHB was significantly higher than those without CHB (20.4% vs. 8.7%; unadjusted OR: 2.68; 95% CI: 2.62 to 2.74; adjusted OR: 2.47; 95% CI: 2.41 to 2.53; p < 0.001) (Table 3). Although STEMI patients with CHB had higher in-hospital mortality than those without CHB irrespective of the location of STEMI, the magnitude of association between CHB and higher risk-adjusted in-hospital mortality was greatest in patients with anterior STEMI. CHB was associated with an approximately 4-fold increase in mortality among patients with anterior STEMI, a 3-fold increase in mortality among patients with other STEMI, but only a 2-fold increase in mortality in patients with inferior STEMI. CHB was also associated with higher risk-adjusted in-hospital mortality in STEMI patients irrespective of the treatment strategy (thrombolysis, PCI, CABG, or no reperfusion) (Table 3).
In patients with CHB complicating STEMI, there was a decline in crude in-hospital mortality from 23.4% in 2003 to 19.1% in 2012 (unadjusted OR per year: 0.97; 95% CI: 0.96 to 0.98, ptrend <0.001). However, when adjusted for demographics, hospital characteristics, and comorbidities, the decreasing trend in in-hospital mortality was not statistically significant (adjusted OR per year: 1.00; 95% CI: 0.99 to 1.01, ptrend = 0.67) (Figure 4A). In-hospital mortality in patients with CHB was higher among those with anterior STEMI or other STEMI compared with those with inferior STEMI (Table 2). Trend analysis showed an increasing trend in in-hospital mortality in patients with CHB complicating anterior STEMI, whereas in-hospital mortality decreased in patients with CHB complicating inferior STEMI (Figures 4B, Online Table 5).
Length of stay
STEMI patients with CHB had longer average LOS than those without CHB (6.87 days vs. 4.68 days; adjusted parameter estimate 1.15; 95% CI: 1.14 to 1.16; p < 0.001). CHB was associated with longer LOS in STEMI patients irrespective of STEMI location and treatment strategy (Table 4). Trend analysis showed a slight but statistically significant decrease in average LOS in patients with CHB and STEMI (Online Table 6).
In this large nationwide study of patients hospitalized with STEMI, we found that even in the contemporary era of prompt reperfusion therapy, CHB remains associated with significantly higher in-hospital mortality. This was true both in patients with anterior and inferior STEMI, although the absolute risk excess was significantly higher in patients with anterior STEMI. Moreover, in patients with CHB complicating STEMI, although there were temporal declines in PPM use rates, risk-adjusted in-hospital mortality remained unchanged during the study period.
Previous studies have reported varying incidence rates of CHB complicating STEMI with more recent studies reporting lower incidence rates (2–8,16). The TAMI (Thrombolysis and Angioplasty in Myocardial Infarction) study group reported that the incidence of CHB in 373 patients with inferior STEMI who received thrombolytic therapy was 13% (5). Data from a study in Israel that examined the incidence rates of CHB in patients hospitalized with AMI in the pre-thrombolytic era (1981 to 1983) compared with those hospitalized in the thrombolytic era (1992 to 1996) showed a decline in incidence rates of CHB from 5.3% to 3.7% (2). The incidence of CHB among 6,676 AMI patients screened for entry into the TRACE (Trandolapril Cardiac Evaluation) randomized trial was 5% (3). Analysis of data from the Worcester Heart Attack Study showed that the overall incidence of CHB in 13,663 AMI patients was 4.1%, with a significant decline in CHB incidence from 1975 to 2005 (7). In comparison, the incidence of CHB complicating STEMI in our study was 2.2%, much lower than what was observed in previously mentioned studies. This likely reflects the overall improvement in the care of STEMI patients over the years, with increasing early use of guideline-recommended invasive reperfusion strategies and adjunctive medical therapies, thus reducing ischemic time, limiting infarct size, and preserving ventricular function, all of which could potentially contribute to lower CHB incidence. In addition, because of the administrative source of our data, underreporting due to coding errors could also have contributed to the low incidence of CHB observed in our study. Although the incidence rate of CHB in our study was lower throughout the study period in comparison to that previously reported, we noted a small but statistically significant increase in the incidence rate from 2003 to 2012. This trend is difficult to explain, but is likely a result of unmeasured confounding, random variation, or more frequent diagnosis as a result of “diagnosis-related group creep” (17) (refers to changes in hospital record documentation to increase case mix and reimbursement), rather than an actual increase in incidence.
Concordant with the findings of previous studies (6,16), we found that the incidence of CHB complicating STEMI was higher patients with inferior STEMI compared with anterior or other STEMI. CHB complicating anterior STEMI is usually within the His-Purkinje system and is related to interruption of septal perfusion accompanied by extensive myocardial damage and significant left ventricular dysfunction (18,19). In inferior STEMI, CHB usually occurs at the atrioventricular (AV) nodal level and is usually related to hypoperfusion of the AV nodal artery, which typically arises from the right coronary artery (20). Consistent with these observations, we found that the negative prognostic impact of CHB was greater in patients with anterior STEMI than it was in patients with inferior STEMI.
Contemporary data on the use of temporary or permanent pacing for CHB in the setting of AMI are scarce. In the Worcester Heart Attack Study, TTVP was used in 53.6% and PPM in 10.1% of the patients with CHB and AMI (7). The GRACE (Analysis of the Global Registry of Acute Coronary Events) trial showed that TTVP was used in 35% and PPM in 5.9% of the patients with high-degree AV block (Mobitz type 2 second-degree heart block or CHB) complicating acute coronary syndromes (both ST-segment elevation and non–ST-segment elevation acute coronary syndromes), with a decline in both TTVP and PPM use rates from 1999 to 2007 (21). In comparison, TTVP was used in 31.8% and PPM in 13.4% of the patients with CHB in our study. Also, although PPM use declined significantly, there was no change in the use of TTVP during the study period. The declining trend in PPM use could be related to contemporary advances in the care of STEMI patients over the years, including increased use of PCI. This could lead to attenuation of the extent of myocardial damage and resolution of peri-infarction CHB, thereby resulting in an increasing proportion of patients in whom CHB is transient and who do not require permanent pacing. Overall, we observed that TTVP use was lower and PPM use was higher in patients with anterior STEMI compared with those with inferior STEMI. In addition, a greater proportion of patients with anterior STEMI who initially received TTVP went on to receive PPM compared with patients with inferior STEMI. This also likely reflects the underlying differences in the pathogenesis of CHB in patients with anterior STEMI compared with those with inferior STEMI.
Patients with STEMI who have CHB have unfavorable short- and long-term prognoses, which are related to the extent of myocardial injury, beyond that attributed to the AV block itself (22). Besides being a marker of extensive myocardial injury, development of CHB in STEMI is also associated with a higher risk for sudden cardiac death (23). In our study, the overall in-hospital mortality in patients with STEMI and CHB was 20.4%, which was >2-fold higher than in-hospital mortality in STEMI patients without CHB. Our findings reaffirm that CHB remains a severe prognostic marker in patients with STEMI in the current PCI era. Previous studies, predominantly from the thrombolytic era, have also reported in-hospital mortality rates between 20% and 30% in patients with CHB in the setting of STEMI (2,3,6). Data on the temporal trends in in-hospital mortality in these patients have been conflicting. Analysis of 13,663 patients with AMI in the Worcester Heart Attack Study showed a significant decline in in-hospital death rates from 1975 to 2005 in patients with concomitant CHB (7). In contrast, data from Israel showed that both short- and long-term mortality rates in patients with CHB did not change from the pre-thrombolytic to the thrombolytic era (2). Analysis of the GRACE registry also did not show a significant decline in in-hospital mortality in patients with high-degree AV block and acute coronary syndromes (21). In our study, although there was a decreasing trend in crude in-hospital mortality from 2003 to 2012, this trend was not statistically significant after risk adjustment. Although the association between CHB and higher in-hospital mortality in STEMI patients who underwent contemporary management was also recently reported by Gang et al. (16), the observation that the adverse mortality associated with CHB has not declined over the last decade is a novel finding of our study.
Certain limitations inherent to the retrospective nature of our study must be acknowledged. First, because NIS is an administrative database, the accuracy of the data depends highly on the training and expertise of the coders. Hence, there is the potential of unrecognized miscoding of diagnosis and procedure codes, leading to underestimation or overestimation of STEMI, CHB, reperfusion, TTVP, or PPM based on ICD-9-CM coding. Also, it is possible that some cases of transient CHB were not coded and were missed as a result. Second, patients not surviving the pre-hospital phase were not included in our study; this could have led to an underestimation of both the incidence of CHB and mortality in patients with CHB in the setting of STEMI. Third, we were not able to differentiate between CHB present at the time of hospital admission versus CHB occurring during the hospitalization. Fourth, we were also unable to examine the temporal relation between reperfusion and the time of occurrence of CHB. Therefore, we could not determine the impact of prompt reperfusion on the likelihood of developing CHB, because some patients may have developed CHB before the institution of reperfusion therapy. Fifth, data on the use of adjunctive medications was not available, and therefore, the impact of these therapies on the change in CHB incidence over time could not be determined. Sixth, we might have underestimated the proportion of patients with CHB and STEMI who underwent PPM implantation because some of these patients might have received an implantable cardioverter defibrillator device during hospitalization for secondary prevention (due to ventricular tachycardia/ventricular fibrillation/cardiac arrest), which is not truly representative of the requirement for permanent pacing alone for CHB. Seventh, some of our findings, although statistically significant, might not be clinically meaningful. Lastly, data in NIS are limited to in-hospital events, and information on long-term outcomes is not available.
CHB is a recognized complication in patients with STEMI and is associated with worse outcomes. Although the incidence of CHB complicating STEMI has increased slightly over the last decade, the absolute incidence of CHB in STEMI patients receiving contemporary management is quite low. Our data show that CHB remains an adverse prognostic marker in STEMI patients in the PCI era, with the association between CHB and worse in-hospital outcomes being more significant in patients with anterior STEMI. Despite advances in STEMI care over the last several years, in-hospital mortality associated with CHB has not declined. Hence, future investigations should focus on developing strategies to improve outcomes in patients with STEMI complicated by CHB. In the meantime, early reperfusion and adjunctive medical therapies for STEMI aimed at attenuating ischemic injury should be aggressively pursued because these could potentially affect the incidence of and outcomes associated with CHB.
COMPETENCY IN MEDICAL KNOWLEDGE: CHB is associated with higher in-hospital mortality in STEMI patients even in the current era of prompt reperfusion therapy. Despite overall advances in STEMI care over the last decade, the incidence of CHB complicating STEMI and in-hospital mortality in STEMI patients with CHB has not declined.
TRANSLATIONAL OUTLOOK: Future research should focus on developing strategies to improve outcomes in patients with CHB complicating STEMI.
For supplemental tables, please see the online version of this article.
Dr. Iwai has received honoraria from Medtronic, Inc., Biotronik, and St. Jude Medical; and has been a consultant for Biosense-Webster. Dr. Bhatt has been a member of the advisory board for Cardax, Elsevier Practice Update Cardiology, Medscape Cardiology, Regado Biosciences; has been a member of the Board of Directors for Boston VA Research Institute, Society of Cardiovascular Patient Care; has been the Chair of American Heart Association Get With The Guidelines Steering Committee; has been a member of the Data Monitoring Committees for Duke Clinical Research Institute, Harvard Clinical Research Institute, Mayo Clinic, Population Health Research Institute; has received honoraria from the American College of Cardiology (Senior Associate Editor, Clinical Trials and News, ACC.org), Belvoir Publications (Editor in Chief, Harvard Heart Letter), Duke Clinical Research Institute (clinical trial steering committees), Harvard Clinical Research Institute (clinical trial steering committee), HMP Communications (Editor in Chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (Associate Editor), Population Health Research Institute (clinical trial steering committee), Slack Publications (Chief Medical Editor, Cardiology Today’s Intervention), WebMD (CME steering committees), and Clinical Cardiology (Deputy Editor); has received research funding from Amarin, AstraZeneca, Biotronik, Bristol-Myers Squibb, Eisai, Ethicon, Forest Laboratories, Ischemix, Medtronic, Pfizer, Roche, Sanofi Aventis, St. Jude Medical, and The Medicines Company; has been a trustee for the American College of Cardiology; and has received unfunded research from FlowCo, PLx Pharma, and Takeda. Dr. Fonarow has been consultant with Astra Zeneca, Bayer, Janssen, and Novartis. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Harikrishnan and Gupta contributed equally to this work. A part of this study was presented at the American Heart Association Scientific Sessions 2014 in Chicago, Illinois.
- Abbreviations and Acronyms
- acute myocardial infarction
- coronary artery bypass grafting
- complete heart block
- confidence interval
- length of stay
- National Inpatient Sample
- odds ratio
- percutaneous coronary intervention
- permanent pacemaker
- ST-segment elevation myocardial infarction
- temporary transvenous pacemaker
- Received July 6, 2015.
- Revision received August 12, 2015.
- Accepted August 17, 2015.
- American College of Cardiology Foundation
- Nicod P.,
- Gilpin E.,
- Dittrich H.,
- et al.
- Harpaz D.,
- Behar S.,
- Gottlieb S.,
- et al.
- Berger P.B.,
- Ruocco N.A. Jr..,
- Ryan T.J.,
- et al.
- Spencer F.A.,
- Jabbour S.,
- Lessard D.,
- et al.
- Healthcare Cost and Utilization Project (HCUP)
- Healthcare Cost and Utilization Project (HCUP)
- Gang U.J.,
- Hvelplund A.,
- Pedersen S.,
- et al.
- Sutton R.,
- Davies M.
- Singh S.M.,
- FitzGerald G.,
- Yan A.T.,
- et al.
- Ginks W.R.,
- Sutton R.,
- Oh W.,
- Leatham A.