Mortality Benefit of Beta Blockade in Patients with Acute Coronary Syndromes Undergoing Coronary Intervention:

β-blockers after myocardial infarction and 1-year clinical outcome - a retrospective study

Background

Long term β-blocker therapy after myocardial infarction (MI) reduces mortality and recurrent MI but evidence for this treatment predates contemporary acute coronary care. β-blocker treatment is a key quality of care indicator in the Swedish national quality register for acute coronary care, Riks-HIA. Between 2011 and 2015 a declining number of MI-patients discharged with a β-blocker from the coronary care unit (CCU) at Helsingborg and other hospitals was reported. This retrospective observational study aimed to investigate the causes for discharge without a β-blocker and relate it to outcome, compared to patients discharged with a β-blocker.

Methods

MI-patients registered in Riks-HIA discharged without β-blocker during 2011–2015 (no-β-group) and a control group (β-group) comprised of patients discharged with β-blocker treatment between January 1 to December 31, 2013, were matched by RIKS-HIA criteria for β-blocker use. Clinical characteristics, date of death, readmission for MI, other cardiovascular events were collected from Riks-HIA and medical records.

Results

The no-β-group included 141 patients, where 65.2% had a justified reason for non-β-blocker use. The β-group included 206 patients. There was no difference in cardiovascular risk factor profile. There were a trend towards a higher number of readmissions for MI in the no-β-group was (n = 8 (5.7%) vs n = 2 (1.0%), p = 0.02), but not mortality (6 (4.3%) vs 2 (1.0%), p = 0.07) and combined readmission for angina pectoris, heart failure, arrhythmias or stroke/TIA (n = 23 (16.3%) vs n = 25 (12.1%), p = 0.27).

Conclusion

A majority of the patients in the no-β-group had a justified absence of a β-blocker. β-blocker treatment post-MI showed a trend towards fewer readmissions for MI. But important quality information is lacking to make a firm conclusion of the effect on outcome.

Effects of Bisoprolol Are Comparable with Carvedilol in Secondary Prevention of Acute Myocardial Infarction in Patients Undergoing Percutaneous Coronary Intervention

Although the benefits of carvedilol have been demonstrated in the era of percutaneous coronary intervention (PCI), very few studies have evaluated the efficacy of bisoprolol in the secondary prevention of acute myocardial infarction (MI) in patients treated with PCI. We hypothesized that the effect of bisoprolol would not be different from carvedilol in post-MI patients. A total of 13,813 patients who underwent PCI were treated either with carvedilol or bisoprolol at the time of discharge. They were enrolled from the Korean Acute MI Registry (KAMIR). After 1:2 propensity score matching, 1,806 patients were enrolled in the bisoprolol group and 3,612 patients in the carvedilol group. The primary end point was the composite of major adverse cardiac events (MACEs), which was defined as cardiac death, nonfatal MI, target vessel revascularization, and coronary artery bypass surgery. The secondary end point was defined as all-cause mortality, cardiac death, nonfatal MI, any revascularization, or target vessel revascularization. After adjustment for differences in baseline characteristics by propensity score matching, the MACE-free survival rate was not different between the groups (HR=0.815, 95% CI:0.614-1.081, p=0.156). In the subgroup analysis, the cumulative incidence of MACEs was lower in the bisoprolol group in patients having a Killip class of III or IV than in the carvedilol group (HR=0.512, 95% CI: 0.263-0.998, p=0.049). The incidence of secondary end points was similar between the two beta-blocker groups. In conclusion, the benefits of bisoprolol were comparable with those of carvedilol in the secondary prevention of acute MI.

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.

Comparison of the effects of metoprolol or carvedilol on serum gamma-glutamyltransferase and uric acid levels among patients with acute coronary syndrome without ST segment elevation

Objective:

Serum gamma-glutamyltransferase (GGT) and uric acid levels measured in patients with acute coronary syndrome without ST segment elevation (NSTEMI) are important in diagnosis and in predicting the prognosis of the disease. There is a limited number of clinical studies investigating the effects of beta-blockers on GGT and uric acid levels in these patients. In our study, we aimed to investigate the effects of beta-blocker therapy on GGT and uric acid levels.

Methods:

We conducted a randomized, prospective clinical study. Hundred patients with NSTEMI were included in this study, and they were divided into two groups. Fifty patients were administered metoprolol succinate treatment (1 × 50 mg), whereas the remaining 50 patients were administered carvedilol treatment (2 × 12.5 mg). Thereafter, all of the patients underwent coronary angiography. Blood samples were taken at the time of admission, at the 1^st month, and 3^rd month to detect GGT and uric acid levels.

Results:

There was no statistically significant difference among the metoprolol or carvedilol groups in terms of the GGT levels measured at the baseline, 1^st month, and 3^rd month (p=0.904 and p=0.573, respectively). In addition, there was no statistically significant difference among the metoprolol or carvedilol groups in terms of uric acid levels measured at the baseline, 1^st month, and 3^rd month (p=0.601 and p=0.601, respectively).

Conclusion:

We found that GGT and uric acid levels did not show any change compared to the baseline values, with metoprolol and carvedilol treatment initiated in the early period in patients with NSTEMI.

Meta-Analysis of Relation Between Oral β-Blocker Therapy and Outcomes in Patients With Acute Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

The aim of the present review was to investigate the association between the use of oral β-blockers and prognosis in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI) treatment. A systematic literature search was conducted in Pubmed (from inception to September 27, 2014) and Embase (Ovid SP, from 1974 to September 29, 2014) to identify studies that compared the outcome of patients with AMI taking oral β-blockers with that of patients not taking after PCI. Systematic review and meta-analysis were performed with random-effects model or fixed-effects model. Ten observational studies with a total of 40,873 patients were included. Use of β-blockers was associated with a reduced risk of all-cause death (unadjusted relative risk 0.58, 95% confidential interval 0.48 to 0.71; adjusted hazard ratio 0.76, 95% confidential interval 0.62 to 0.94). The potential benefit of β-blockers in preventing all-cause death was not similar in all population but was restricted to those with reduced ejection fraction, with low use proportion of other secondary prevention drugs or with non-ST-segment elevation myocardial infarction. The association between the use of β-blockers and improved survival rate was significant in ≤1-year follow-up duration. Rates of cardiac death, myocardial infarction, and heart failure readmission in patients using β-blockers were not significantly different from those in patients without β-blocker therapy. In conclusion, there is lack of evidence to support routine use of β-blockers in all patients with AMI who underwent PCI. Further trials are urgently needed to address the issue.

Benefit of β-blocker treatment for patients with acute myocardial infarction and preserved systolic function after percutaneous coronary intervention

OBJECTIVE

β-blockers are the standard treatment for myocardial infarction (MI) based on evidence from the pre-thrombolytic era. The aim of this study was to examine the effect of β-blocker treatment in patients with acute MI and preserved systolic function in the era of percutaneous coronary intervention (PCI).

METHODS

We analysed a multicentre registry and identified 3019 patients who presented with acute MI between 2004 and 2009. Patients were treated with PCI, had left ventricular EFs ≥50% according to echocardiograms that were performed during the index PCI, and were alive at the time of discharge. The association between β-blocker use after discharge and mortality (all-cause death and cardiac death) within 3 years was examined.

RESULTS

Patients who were not treated with β-blockers (n=595) showed higher rates of all-cause death and cardiac death compared to patients treated with β-blockers (10.8% vs 5.7%, p<0.001, 7.6% vs 2.6%, p<0001). The multivariate Cox proportional hazards model showed that β-blocker treatment was associated with a significant reduction in all-cause death (adjusted HR 0.633, 95% CI 0.464 to 0.863; p=0.004) and cardiac death (adjusted HR 0.47, 95% CI 0.32 to 0.70; p<0.001). Comparable results were obtained after propensity score matching.

CONCLUSIONS

β-blocker treatment was associated with reduced long term mortality in patients with acute MI and preserved systolic function who received PCI.

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.

Day 1 care in patients with non-ST-segment elevation myocardial infarction

In 2007, the American College of Cardiology/American Heart Association and the European Society of Cardiology updated their guidelines for the management of patients with non-ST-segment elevation myocardial infarction (NSTEMI). Based on evidence from recent clinical studies, both 2007 guidelines recommend early risk stratification, administration of appropriate pharmacologic therapy, and selective use of percutaneous coronary intervention in order to reduce morbidity and mortality in these patients. In this article, we focus on management of patients with NSTEMI during the first 24 h of presentation and present a clinical scenario to illustrate the current guidelines-based management strategy.

Drugs for cardiovascular disease prevention in women: implications of the AHA Guidelines--2007 Update

Lifestyle interventions constitute the initial strategy for the primary and secondary prevention of cardiovascular disease in women. However, pharmacotherapy is often indicated for control of major cardiovascular risk factors, and abundant clinical trial data support the morbidity and mortality benefit of a number of categories of drug therapy following a coronary event. Although women have increasingly been enrolled in clinical trials of pharmacotherapy, under representation of women in most research studies limits the gender-specific assessment of outcomes. Equally importantly, recent randomized clinical trial data have highlighted inappropriate preventive therapies for women (i.e. those lacking effectiveness and potentially imparting harm). Decision-making data for drug therapy for women also derive from a number of clinical trials conducted solely in women. The drug classes reviewed in this article include omega-3 fatty acids, aspirin, ACE inhibitors and angiotensin II receptor antagonists or blockers, beta-adrenoceptor antagonists (beta-blockers), aldosterone antagonists, antioxidants, folic acid and vitamins B(6) and B(12), and menopausal hormone therapy and selective estrogen-receptor modulators. Information is sparse regarding specific cardiovascular pharmacotherapies for elderly women, and women of racial and ethnic minorities. Owing to the under representation of the subset of women in many trials, analysis by age, race and ethnicity is not appropriate. This information gap presents a major challenge for future studies, as these subgroups constitute populations of women at high cardiovascular risk.

Medical treatment of patients with heart failure or left ventricular dysfunction undergoing percutaneous coronary intervention

Management of ischemic patients with pre-existing or new-onset left ventricular (LV) dysfunction poses a special challenge in terms of the timing of percutaneous coronary intervention (PCI) and appropriate adjunctive medications to optimize outcome while minimizing risk. In a systematic fashion, this review attempts to provide a management scheme for patients with heart failure or LV dysfunction that present with stable angina, ST-segment elevation myocardial infarction, or unstable angina/non-ST-segment elevation myocardial infarction. By addressing therapeutic approaches to acute or decompensated heart failure and timing of coronary angiography based on severity of ischemia, we provide evidence-based recommendations for medications to initiate before, during, and following PCI.

Revascularization and cardioprotective drug treatment in myocardial infarction patients: how do they impact on patients' survival when delivered as usual care

Background

Randomized clinical trials showed the benefit of pharmacological and revascularization treatments in secondary prevention of myocardial infarction (MI), in selected population with highly controlled interventions. The objective of this study is to measure these treatments' impact on the cardiovascular (CV) mortality rate among patients receiving usual care in the province of Quebec.

Methods

The study population consisted of a "naturalistic" cohort of all patients ≥ 65 years old living in the Quebec province, who survived a MI (ICD-9: 410) in 1998. The studied dependant variable was time to death from a CV disease. Independent variables were revascularization procedure and cardioprotective drugs. Death from a non CV disease was also studied for comparison. Revascularization procedure was defined as percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass graft (CABG). The exposure to cardioprotective drugs was defined as the number of cardioprotective drug classes (Acetylsalicylic Acid (ASA), Beta-Blockers, Angiotensin-Converting Enzyme (ACE) Inhibitors, Statins) claimed within the index period (first 30 days after the index hospitalization). Age, gender and a comorbidity index were used as covariates. Kaplan-Meier survival curves, Cox proportional hazard models, logistic regressions and regression trees were used.

Results

The study population totaled 5596 patients (3206 men; 2390 women). We observed 1128 deaths (20%) within two years following index hospitalization, of them 603 from CV disease. The CV survival rate at two years is much greater for patients with revascularization, regardless of pharmacological treatments. For patients without revascularization, the CV survival rate increases with the number of cardioprotective drug classes claimed. Finally, Cox proportional hazard models, regression tree and logistic regression analyses all revealed that the absence of revascularization and, to a lower extent, absence of cardioprotective drugs were major predictors for CV death, even after adjusting for age, gender and comorbidity.

Conclusion

Considering usual care management of MI in the province of Quebec in 1998, CV survival is positively correlated to the presence of a revascularization procedure and to the intensity of cardioprotective pharmacological treatment. These results are coherent with data from randomized control trials.

Effects of metoprolol therapy on cardiac troponin-I levels after elective percutaneous coronary interventions

AIMS

Beta-blockers (BBs) have been shown to improve survival and reduce the risk of re-infarction in patients following myocardial infarction. There are conflicting data about the effects of BB therapy on cardiac biomarkers after percutaneous coronary interventions (PCIs). The aim of the study was to investigate the effects of BB use on cardiac troponin-I (cTnI) levels in patients who had undergone elective PCI.

METHODS AND RESULTS

In this prospective study, 287 patients with coronary artery disease were included. Patients were randomized either to BB or control groups prior to the intervention. Blood samples for cTnI were obtained before and at 6, 24, and 36 h after the procedure. Of the 287 patients included, 143 received metoprolol succinate 100 mg/day, and 144 received no BB and served as the control group. Baseline clinical characteristics of both groups, except for history of coronary artery bypass graft surgery, were similar. We observed no significant difference in the elevation of cTnI levels between the two groups after PCI (BB group, 17 patients, 11.9%; control group, 10 patients, 6.9%; P=0.2).

CONCLUSION

Metoprolol succinate therapy seems to have no cardioprotective effect in limiting troponin-I rise after PCI.