Impact of acute beta-blocker therapy for patients with non-ST-segment elevation myocardial infarction

Importance of reassessment to identify trajectories of chronic transition of clinical indicators in post-myocardial infarction management

Despite advances in multidisciplinary acute care for myocardial infarction (MI), the clinical need to manage heart failure and elevated mortality risks in the remote phase of MI remains unmet. Various prognostic models have been established using clinical indicators obtained during the acute phase of MI; however, most of these indicators also show chronic changes in the post-MI phase. Although relevant guidelines recommend follow-up assessments of some clinical indicators in the chronic phase, systematic reassessment has not yet been fully established and implemented in a real-world clinical setting. Therefore, clinical evidence of the impact of such chronic transitions on the post-MI prognosis is lacking. We speculate that post-MI reassessment of key clinical indicators and the impact of their chronic transition patterns on long-term prognoses can improve the quality of post-MI risk stratification and help identify residual risk factors. Several recent studies have investigated the impact of the chronic transition of some clinical indicators, such as serum albumin level, mitral regurgitation, and left-ventricular dysfunction, on post-MI prognosis. Interestingly, even in MI survivors with these indicators within their respective normal ranges in the acute phase of MI, chronic transition to an abnormal range was associated with worsening cardiovascular outcomes. On the basis of these recent insights, we discuss the clinical significance of post-MI reassessment to identify the trajectories of several clinical indicators and elucidate the potential residual risk factors affecting adverse outcomes in MI survivors.

Early beta-blocker therapy improves in-hospital mortality of patients with non-ST-segment elevation myocardial infarction - a meta-analysis

BACKGROUND

Although current guidelines endorse early beta-blocker therapy in stable patients with STEMI, there is no clear recommendation on the early use of these drugs in patients with NSTEMI.

METHODS

Literature search was conducted by 3 independent researchers using PubMed/MEDLINE, CDSR, CENTRAL, CCAs, EBM Reviews, Web of Science and LILACS. Studies were eligible if (P) patients included were ≥ 18 years of age and had non-ST-segment elevation myocardial infarction (NSTEMI), (I) early (<24 h) treatment with intravenous or oral beta-blockers was compared to (C) no treatment with beta-blockers and data on (O) in-hospital mortality and/or in-hospital cardiogenic shock were depicted. Odds ratios and 95% confidence intervals were calculated using random effects models with the Mantel-Haenszel method. The Hartung-Knapp-Sidik-Jonkman method was used as estimator for τ2.

RESULTS

977 records were screened for eligibility, which led to the inclusion of 4 retrospective, nonrandomized, observational cohort studies comprising a total of N = 184,951 patients. After pooling of the effect sizes, early therapy with beta-blockers resulted in a reduction of in-hospital mortality (OR 0.43 [0.36-0.51], p = 0.0022) despite no significant effect on the prevalence of cardiogenic shock (OR 0.36 [0.07-1.91], p = 0.1196).

CONCLUSION

Early treatment with beta-blockers was associated with an attenuation of in-hospital mortality despite no increase in cardiogenic shock. Thus, early therapy with these drugs could elicit beneficial effects on top of reperfusion therapy, similar to the effects seen in STEMI-patients. The low number of studies (k = 4) has to be considered when interpreting the findings of this analysis.

Beta-Blockers in the Prevention and Treatment of Ischemic Heart Disease: Evidence and Clinical Practice

Coronary artery disease (CAD) is the most prevalent cardiovascular disease characterized by atherosclerotic plaque buildup that can lead to partial or full obstruction of blood flow in the coronary arteries. Treatment for CAD involves a combination of lifestyle changes, pharmacologic therapy, and modern revascularization procedures. Beta-adrenoceptor antagonists (or beta-blockers) have been widely used for decades as a key therapy for CAD. In this review, prior studies are examined to better understand beta-adrenoceptor antagonist use in patients with acute coronary syndrome, stable coronary heart disease, and in the perioperative setting. The evidence for the benefit of beta-blocker therapy is well established for patients with acute myocardial infarction, but it diminishes as the time from the index cardiac event elapses. The evidence for benefit in the perioperative setting is not strong.

Adherence to Cardiac Practice Guidelines in the Management of Non-ST-Elevation Acute Coronary Syndromes: A Systematic Literature Review

BACKGROUND

In the management of non-ST-elevation acute coronary syndrome (NSTACS) a gap between guideline-recommended care and actual practice has been reported. A systematic overview of the actual extent of this gap, its potential impact on patient-outcomes, and influential factors is lacking.

OBJECTIVE

To examine the extent of guideline adherence, to study associations with the occurrence of adverse cardiac events, and to identify factors associated with guideline adherence.

METHOD

Systematic literature review, for which PUBMED, EMBASE, CINAHL, and the Cochrane library were searched until March 2016. Further, a manual search was performed using reference lists of included studies. Two reviewers independently performed quality-assessment and data extraction of the eligible studies.

RESULTS

Adherence rates varied widely within and between 45 eligible studies, ranging from less than 5.0 % to more than 95.0 % for recommendations on acute and discharge pharmacological treatment, 34.3 % - 93.0 % for risk stratification, and 16.0 % - 95.8 % for performing coronary angiography. Seven studies indicated that higher adherence rates were associated with lower mortality. Several patient-related (e.g. age, gender, co-morbidities) and organization-related (e.g. teaching hospital) factors influencing adherence were identified.

CONCLUSION

This review showed wide variation in guideline adherence, with a substantial proportion of NST-ACS patients possibly not receiving guideline-recommended care. Consequently, lower adherence might be associated with a higher risk for poor prognosis. Future research should further investigate the complex nature of guideline adherence in NST-ACS, its impact on clinical care, and factors influencing adherence. This knowledge is essential to optimize clinical management of NSTACS patients and could guide future quality improvement initiatives.

Relationship Between β-Blocker Therapy at Discharge and Clinical Outcomes in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

BACKGROUND

The evidence supporting the use of β-blockers in patients with acute coronary syndrome after successful percutaneous coronary intervention has been inconsistent and scarce.

METHODS AND RESULTS

Between March 1, 2009, and December 30, 2014, a total of 3180 eligible patients with acute coronary syndrome undergoing percutaneous coronary intervention were consecutively enrolled. The primary end point was all-cause death and the secondary end point was a composite of all-cause death, nonfatal myocardial infarction, heart failure readmission, and cardiogenic hospitalization. Patients were compared according to the use of β-blockers at discharge. Compared with the no β-blocker group, the risk of all-cause death was significantly lower in the β-blocker group (hazard ratio [HR], 0.33; 95% CI, 0.17-0.65 [P=0.001]). A consistent result was obtained in multiple adjusted model and propensity score-matched analysis. The use of β-blockers was also associated with decreased risk of composite of adverse cardiovascular events (HR, 0.47; 95% CI, 0.28-0.81 [P=0.006]), although statistical significance disappeared after multivariable adjustment and propensity score matching. Furthermore, we performed post hoc analysis for the subsets of patients and the results revealed that patients with non-ST-segment elevation myocardial infarction benefited the most from β-blocker therapy at discharge (HR, 0.04; 95% CI, 0.00-0.27 [P=0.001]), and the use of <50% of target dose was significantly associated with better outcome compared with no β-blocker use, rather than ≥50% of target dose.

CONCLUSIONS

The administration of relatively low β-blocker dose is associated with improved clinical outcomes among patients with acute coronary syndrome after successful percutaneous coronary intervention, especially for patients with non-ST-segment elevation myocardial infarction.

Acute management of unstable angina and non-ST segment elevation myocardial infarction

Non-ST segment elevation coronary syndrome usually results from instability of an atherosclerotic plaque, with subsequent activation of platelets and several coagulation factors. Its treatment aims to reduce the ischemic pain, limiting myocardial damage and decreasing mortality. Several antiplatelet and anticoagulation agents have been proven useful, and new drugs have been added to the therapeutic armamentarium in the search for higher anti-ischemic efficacy and lower bleeding rates. Despite the advances, the mortality, infarction and readmission rates remain high.

Comparison of Early Versus Delayed Oral β Blockers in Acute Coronary Syndromes and Effect on Outcomes

The aim of this study was to determine if earlier administration of oral β ​blocker therapy in patients with acute coronary syndromes (ACSs) is associated with an increased short-term survival rate and improved left ventricular (LV) function. We studied 11,581 patients enrolled in the International Survey of Acute Coronary Syndromes in Transitional Countries registry from January 2010 to June 2014. Of these patients, 6,117 were excluded as they received intravenous β blockers or remained free of any β ​blocker treatment during hospital stay, 23 as timing of oral β ​blocker administration was unknown, and 182 patients because they died before oral β blockers could be given. The final study population comprised 5,259 patients. The primary outcome was the incidence of in-hospital mortality. The secondary outcome was the incidence of severe LV dysfunction defined as an ejection fraction <40% at hospital discharge. Oral β blockers were administered soon (≤24 hours) after hospital admission in 1,377 patients and later (>24 hours) during hospital stay in the remaining 3,882 patients. Early β ​blocker therapy was significantly associated with reduced in-hospital mortality (odds ratio 0.41, 95% CI 0.21 to 0.80) and reduced incidence of severe LV dysfunction (odds ratio 0.57, 95% CI 0.42 to 0.78). Significant mortality benefits with early β ​blocker therapy disappeared when patients with Killip class III/IV were included as dummy variables. The results were confirmed by propensity score-matched analyses. In conclusion, in patients with ACSs, earlier administration of oral β ​blocker therapy should be a priority with a greater probability of improving LV function and in-hospital survival rate. Patients presenting with acute pulmonary edema or cardiogenic shock should be excluded from this early treatment regimen.

National assessment of early β-blocker therapy in patients with acute myocardial infarction in China, 2001-2011: The China Patient-centered Evaluative Assessment of Cardiac Events (PEACE)-Retrospective AMI Study

BACKGROUND

Since 2007, clinical practice guidelines have recommended β-blocker therapy early in the course of acute myocardial infarction (AMI) for patients who are not at high risk for complications. Our objective was to perform a national quality assessment of early β-blocker use during hospitalization for AMI over the past decade in China.

METHODS

We conducted medical record review of a nationally representative sample of patients admitted to Chinese hospitals with AMI and studied those without absolute contraindications to β-blocker therapy in 2001, 2006, and 2011. We evaluated the use, type, and dose of β-blockers within the first 24 hours of admission over time and identified predictors of not using this treatment both in ideal candidates and in those with risk factors for cardiogenic shock.

RESULTS

Among 14,241 patients with AMI (representing 43,165 patients in 2001, 106,167 patients in 2006, and 221,874 patients in 2011 in China, respectively), 45.1% had no contraindications to early β-blocker therapy; 21.1% had risk factors for cardiogenic shock but no absolute contraindication. β-blocker use in ideal patients was 54.3% in 2001, 67.8% in 2006, and 61.8% in 2011 (P = .28 for trend). Predictors of nontreatment were older age, lower systolic blood pressure, lower heart rate, absence of chest discomfort, and admission to a nonteaching hospital. Use in patients with risk factors for cardiogenic shock was 42.6% in 2001, 59.5% in 2006, and 52.9% in 2011 (P = .31 for trend). Metoprolol was used most frequently (91.5%), but dosages were often below those recommended in guidelines.

CONCLUSIONS

The use of early β-blocker therapy for patients with AMI in China is suboptimal, with underuse in patients who could benefit and substantial use among those who might be harmed. Patterns of use have not changed over time, thus creating an important target of efforts to improve quality of care for AMI.

Effect of early bisoprolol administration on ventricular arrhythmia and cardiac death in patients with non-ST elevation myocardial infarction

OBJECTIVE

To investigate the impact of early oral beta blockade in patients presenting with acute non-ST elevation myocardial infarction (NSTEMI).

METHODS

We retrospectively identified 890 consecutive patients presenting with NSTEMI to a single UK centre from 2012 to 2014. Included patients all received standardised antiplatelet therapy plus low-dose oral bisoprolol (1.25-2.5 mg) within 4 h (mean 2.2±1.36; 'Early Group') or within 5-24 h (mean 15.4±5.7; 'Late Group') of presentation. Patients were followed up for the duration of hospital stay with the incidence of major adverse cardiovascular events (MACE-defined as ventricular arrhythmia, cardiac death or repeat infarction) set as the primary outcome. Multivariate logistic regression models analysed early versus late bisoprolol administration and adjusted for potential confounders.

RESULTS

399 patients were included. Of the patient parameters, only the GRACE score was significantly different between the early (n=99, GRACE 164.5±29.6) and late (n=300, GRACE 156.7±31.4) groups (p=0.033). The early group had significantly fewer ventricular arrhythmias (1 vs 20, p=0.034), cardiac deaths (0 vs 13, p=0.044) and consequently MACE (1 vs 27, p=0.005) than the late group. After adjusting for the confounders of pulse, blood pressure, smoking and creatinine, logistic regression analysis identified early bisoprolol administration as protective for ventricular arrhythmia (p=0.038, OR 0.114, CI 0.015 to 0.885) and MACE (p=0.011, OR 0.064, CI 0.008 to 0.527). There was one episode of symptomatic bradycardia in the late group.

CONCLUSIONS

This study suggests that low-dose oral bisoprolol administered to patients with NSTEMI within 4 h of admission may be protective and lead to reduced inpatient MACE.

Nonantithrombotic medical options in acute coronary syndromes: old agents and new lines on the horizon

Acute coronary syndromes (ACS) constitute a spectrum of clinical presentations ranging from unstable angina and non-ST-segment elevation myocardial infarction to ST-segment myocardial infarction. Myocardial ischemia in this context occurs as a result of an abrupt decrease in coronary blood flow and resultant imbalance in the myocardial oxygen supply-demand relationship. Coronary blood flow is further compromised by other mechanisms that increase coronary vascular resistance or reduce coronary driving pressure. The goals of treatment are to decrease myocardial oxygen demand, increase coronary blood flow and oxygen supply, and limit myocardial injury. Treatments are generally divided into disease-modifying agents or interventions that improve hard clinical outcomes and other strategies that can reduce ischemia. In addition to traditional drugs such as β-blockers and inhibitors of the renin-angiotensin-aldosterone system, newer agents have expanded the number of molecular pathways targeted for treatment of ACS. Ranolazine, trimetazidine, nicorandil, and ivabradine are medications that have been shown to reduce myocardial ischemia through diverse mechanisms and have been tested in limited fashion in patients with ACS. Attenuating the no-reflow phenomenon and reducing the injury compounded by acute reperfusion after a period of coronary occlusion are active areas of research. Additionally, interventions aimed at ischemic pre- and postconditioning may be useful means by which to limit myocardial infarct size. Trials are also underway to examine altered metabolic and oxygen-related pathways in ACS. This review will discuss traditional and newer anti-ischemic therapies for patients with ACS, exclusive of revascularization, antithrombotic agents, and the use of high-intensity statins.

Total beta-adrenoceptor knockout slows conduction and reduces inducible arrhythmias in the mouse heart

INTRODUCTION

Beta-adrenoceptors (β-AR) play an important role in the neurohumoral regulation of cardiac function. Three β-AR subtypes (β(1), β(2), β(3)) have been described so far. Total deficiency of these adrenoceptors (TKO) results in cardiac hypotrophy and negative inotropy. TKO represents a unique mouse model mimicking total unselective medical β-blocker therapy in men. Electrophysiological characteristics of TKO have not yet been investigated in an animal model.

METHODS

In vivo electrophysiological studies using right heart catheterisation were performed in 10 TKO mice and 10 129SV wild type control mice (WT) at the age of 15 weeks. Standard surface ECG, intracardiac and electrophysiological parameters, and arrhythmia inducibility were analyzed.

RESULTS

The surface ECG of TKO mice revealed a reduced heart rate (359.2±20.9 bpm vs. 461.1±33.3 bpm; p<0.001), prolonged P wave (17.5±3.0 ms vs. 15.1±1.2 ms; p = 0.019) and PQ time (40.8±2.4 ms vs. 37.3±3.0 ms; p = 0.013) compared to WT. Intracardiac ECG showed a significantly prolonged infra-Hisian conductance (HV-interval: 12.9±1.4 ms vs. 6.8±1.0 ms; p<0.001). Functional testing showed prolonged atrial and ventricular refractory periods in TKO (40.5±15.5 ms vs. 21.3±5.8 ms; p = 0.004; and 41.0±9.7 ms vs. 28.3±6.6 ms; p = 0.004, respectively). In TKO both the probability of induction of atrial fibrillation (12% vs. 24%; p<0.001) and of ventricular tachycardias (0% vs. 26%; p<0.001) were significantly reduced.

CONCLUSION

TKO results in significant prolongations of cardiac conduction times and refractory periods. This was accompanied by a highly significant reduction of atrial and ventricular arrhythmias. Our finding confirms the importance of β-AR in arrhythmogenesis and the potential role of unspecific beta-receptor-blockade as therapeutic target.

Adherence to ACC/AHA performance measures for myocardial infarction in six Middle-Eastern countries: association with in-hospital mortality and clinical characteristics

BACKGROUND/OBJECTIVES

This study assesses adherence to performance measures for acute myocardial infarction (AMI) in six Middle-Eastern countries, and its association with in-hospital mortality. Few studies have previously assessed these performance measures in the Middle East.

METHODS

This cohort study followed 5813 patients with suspected AMI upon admission to discharge. Proportions of eligible participants receiving the following performance measures were calculated: medications within 24 hours of admission (aspirin and beta-blocker) and on discharge (aspirin, beta-blockers, angiotensin converting enzyme inhibitors [ACEI], and lipid-lowering therapy), reperfusion therapy, and low-density lipoprotein (LDL) cholesterol measurement. A composite adherence score was calculated. Associations between performance measures and clinical characteristics were assessed using multivariate logistic regression.

RESULTS

Adherence was above 90% for aspirin, reperfusion, and lipid-lowering therapies; between 60% and 82% for beta-blockers, ACEI, statin therapy, time-to-balloon within 90 minutes, and LDL-cholesterol measurement; and 33% for time-to-needle within 30 minutes. After adjustment, factors associated with high composite performance score (>85%) included Asian ethnicity (Odds Ratio, OR=1.3; p=0.01) and history of hyperlipidemia (OR=1.4; p=0.001). Factors associated with a lower score included atypical symptoms (OR=0.6; p=0.003) and high GRACE score (OR=0.6; p<0.001). Lower in-hospital mortality was associated with provision of reperfusion therapy (OR=0.54, p=0.047) and beta-blockers within 24 hours (OR=0.33, p=0.005).

CONCLUSIONS

Overall adherence was lowest among the highest-risk patients. Lower in-hospital mortality was independently associated with adherence to early performance measures, comprising observational evidence for their effectiveness in a Middle East cohort. These data provide a focus for regional quality improvement initiatives and research.

Reasons for non-use of proven pharmacotherapeutic interventions: systematic review and framework development

RATIONALE, AIMS AND OBJECTIVES

The quality of patient care and safety is dependent on addressing both errors of commission (e.g. overuse of medications) and errors of omission (e.g. patients receiving too little care). Despite guidelines recommending the use of certain proven pharmacotherapeutic interventions, a large gap exists between the patients that have an indication for, and those that actually receive such interventions. To address how the rate of implementation of proven interventions can be improved is dependent on a comprehensive knowledge of the factors contributing to their underuse. The aim of the review is to create an evidence-based framework of reasons why eligible patients do not receive proven pharmacotherapeutic interventions.

METHODS

A systemic review of the published reasons for non-use based on the Cochrane methodology.

RESULTS

The systematic review identified 67 articles meeting the inclusion criteria. The reasons for non-use were extracted from the studies and a framework was created from the results.

CONCLUSIONS

The factors associated with lack of implementation of proven pharmacotherapeutic interventions are complex and heterogeneous but can be understood from the perspectives of clinicians, patients and health care delivery systems. Efforts to increase the utilization of proven interventions should focus on disease/intervention-specific programmes that take into account the identified modifiable clinician, patient and system factors.

Impact of an acute coronary syndrome pathway in achieving target heart rate and utilization of evidence-based doses of beta-blockers

Beta-blockers remain a cornerstone of therapy in the management of acute coronary syndrome (ACS). The 2007 American College of Cardiology/American Heart Association unstable angina/non-ST elevation myocardial infarction guideline revisions recommend a target heart rate (HR) of 50-60 beats per minute (bpm). Despite improved trends toward utilization of beta-blockers therapy, beta-blockers continue to be underdosed. Guideline-based tools have been shown to improve adherence to evidence-based therapy in patients with ACS. Implementation of a standardized ACS pathway would lead to titration of beta-blockers to recommended dosages with improved HRs in eligible patients. The ACS clinical protocol was implemented at the University of Toledo Medical Center in May 2007. A retrospective study of 516 patients admitted during a comparable 6-month period, before and after the institution of the protocol, was conducted. The preprotocol and protocol group included 237 and 279 patients, respectively. Patient information extracted from the medical records included age, gender, HR on admission, blood pressure on admission, duration of hospital stay, preadmission use of beta-blocker, type of beta-blocker and dosage, discharge beta-blocker and dosage, peak troponin levels, and therapeutic intervention. A target HR of less than 60 bpm was achieved in 19% of the protocol group, as compared with 6% in the preprotocol group (P < 0.001). The protocol group had a significantly lower mean discharge HR than the preprotocol group (67 vs. 74 bpm; P < 0.001). The mean discharge dose of metoprolol in the protocol group was noted to be significantly higher (118 vs. 80 mg/d; P < 0.001). The institution of an ACS clinical pathway led to utilization of beta-blockers in significantly higher dosages, resulting in improved HR control and increased attainment of target HR.

Has the ClOpidogrel and Metoprolol in Myocardial Infarction Trial (COMMIT) of early β-blocker use in acute coronary syndromes impacted on clinical practice in Canada? Insights from the Global Registry of Acute Coronary Events (GRACE)

BACKGROUND

The COMMIT/CCS-2 trial, published in 2005, demonstrated no net benefit of early β-blocker (BB) therapy in acute coronary syndromes (ACS). We sought to assess the short-term impact of this landmark trial by comparing the use of early BB therapy in patients with a broad spectrum of ACS before and after 2005.

METHODS

Using data from the Global Registry of Acute Coronary Events and Canadian Registry of Acute Coronary Events, we compared the rates of BB use within the first 24 hours of presentation in the periods 1999 to 2005 and 2006 to 2008, after stratifying patients by the type of ACS (ST-segment elevation myocardial infarction [STEMI] and non-ST-segment elevation ACS [NSTEACS]) and clinical presentation.

RESULTS

Of the 14,231 patients with ACS, 77.7% received BB therapy within 24 hours of presentation (78.5% and 77.4% in the STEMI and NSTEACS groups, respectively). The early use of BB declined in the STEMI group (80.3% to 76.7%, P = .005) but increased in the NSTEACS group (75.4% to 78.9%, P < .001) after 2005. Long-term BB use, higher systolic blood pressure, and higher heart rate were independent predictors of early BB use. Conversely, patients who were female, older, Killip class >1, and had cardiac arrest at presentation were less likely to receive early BB. Multivariable analysis showed a trend toward lower use of BB among patients with STEMI (adjusted odds ratio 0.76, 95% CI 0.57-1.00, P = .055) and a trend toward more frequent BB use among patients with NSTEACS (adjusted odds ratio 1.22, 95% CI 0.96-1.55, P = .11) after 2005. The temporal trends in the early use of BB differed between patients with STEMI and patients with NSTEACS (P for interaction with period <.001).

CONCLUSIONS

Most patients with STEMI or NSTEACS were treated with early BB therapy. In accordance with the COMMMIT/CCS-2 trial, patients with lower systolic blood pressure and higher Killip class in the "real world" less frequently received early BB therapy. Since the publication of COMMIT/CCS-2, there has been no significant change in the use of BB in patients with STEMI or NSTEACS after controlling for their clinical characteristics.

Physician practice patterns in acute coronary syndromes: an initial report of an individual quality improvement program

The American College of Cardiology and the American Heart Association guidelines are the nationally accepted standards for the treatment of patients with acute coronary syndromes. Despite this recognition, adherence to guideline recommendations remains suboptimal with 25% of opportunities to provide guideline appropriate care missed. To address performance gaps related to acute coronary syndrome care and improve patient outcomes, a performance improvement (PI) initiative was designed for cardiologists and emergency department physicians. As an American Medical Association-approved, standardized continuing medical education initiative, participating physicians can earn up to 20 American Medical Association-PRA Category 1 Credits by completing 2 phases of self-assessment in addition to developing and implementing a PI plan to address self-identified areas where improvement in patient care is needed. As the second in a series of 3 articles, this article describes the initial data submitted by 101 participating physicians and how their treatment practices compared with American College of Cardiology/American Heart Association guidelines as well as with current national standards. Overall, participating physicians meet guideline expectations with performance and documentation of a 12-lead electrocardiography, measurement of cardiac biomarkers, and administration of aspirin. Identified areas of improvement were the standardization of treatment protocols, use of risk assessment scores, appropriate dosing of anticoagulants, and improvement in patient treatment times. A noted challenge of this PI initiative is the low rate of physician participation, with fewer than 10% of registered physicians actively submitting patient data. This fact may reflect several barriers to PI, such as: (1) lack of time to collect and submit data, (2) the belief that current practices do not need to be improved, and (3) the need for system-based improvements.

Relation of mortality to failure to prescribe beta blockers acutely in patients with sustained ventricular tachycardia and ventricular fibrillation following acute myocardial infarction (from the VALsartan In Acute myocardial iNfarcTion trial [VALIANT] Registry)

Sustained ventricular arrhythmias and heart failure are well-recognized complications after acute myocardial infarction (AMI) and have been associated with worse outcomes and increased mortality. The use of and outcomes associated with acute beta-blocker therapy in patients with AMI complicated by sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and heart failure were investigated. Of 5,391 patients in the VALIANT Registry, sustained VT/VF occurred in 306 (5.7%), with an in-hospital mortality rate of 20.3%. Multivariable logistic regression identified sustained VT/VF as a major predictor of in-hospital death (relative risk 4.18, 95% confidence interval 2.91 to 5.93). Of those with sustained VT/VF, 55.2% were treated with intravenous or oral beta blockade in the first 24 hours. After adjusting for baseline characteristics, propensity for acute beta-blocker use, and the interaction between Killip classification and beta-blocker therapy, beta-blocker therapy within 24 hours was associated with decreased in-hospital mortality in patients with sustained VT/VF (relative risk 0.28, 95% confidence interval 0.10 to 0.75, p = 0.013) without evidence of worsening heart failure. Patients with sustained VT/VF were less likely to receive beta blockers within 24 hours (p = 0.001). In conclusion, sustained VT/VF was common after AMI. In patients with sustained VT/VF, beta-blocker therapy in the first 24 hours after AMI was associated with decreased early mortality without worsening heart failure. Unfortunately, beta blockers were underused acutely in patients with sustained VT/VF.