Usefulness of heart rate to predict one-year mortality in patients with atrial fibrillation and acute myocardial infarction (from the OMEGA trial)

De novo and pre-existing atrial fibrillation in acute coronary syndromes: impact on prognosis and cardiovascular events in long-term follow-up

AIMS

The aim of the study was to compare in-hospital and long-term prognosis in patients with acute coronary syndromes (ACS) and de novo vs. pre-existing atrial fibrillation (AF). Atrial fibrillation increases the risk of serious adverse events including death in patients with ACS. However, it is unclear whether de novo and pre-existing AF portend a different risk.

METHODS AND RESULTS

We analysed the incidence, clinical characteristics, and in-hospital and long-term outcomes in patients with AF and ACS based on combined data from Polish Registry of Acute Coronary Syndrome (PL-ACS) (n = 581 843) and SILICARD (n = 852 063) databases. Atrial fibrillation at admission was diagnosed in of 6.16% patients [de novo: 1129 (2.46%); pre-existing: 1691 (3.7%)]. Groups were compared (N = 1023 vs. 1023) after matching for relevant clinical factors. De novo and pre-existing AF differed in in-hospital diuretic (52% vs. 58%; P = 0.008) and aldosterone inhibitor (27.5% vs. 32.5%; P = 0.02) use, Thrombolysis In Myocardial Infarction (TIMI) flow before percutaneous coronary intervention (P = 0.016), and diuretic (52.1% vs. 58%; P = 0.008) and oral anticoagulant (27.5% vs. 32.5%; P = 0.018) use at discharge. In-hospital mortality in the de novo AF group was significantly higher (13.1% vs. 8.31%; P = 0.0005). Post-discharge 12-month survival was similar between groups (14.5% vs. 15.3%, P = 0.63). Long-term re-hospitalization due to heart failure (22.7% vs. 17.2%; P < 0.005) and medical contact due to AF (48.4% vs. 26.1%, P < 0.0001) rates were higher in the group with pre-existing AF, without the difference of stroke or myocardial infarction occurrence.

CONCLUSION

De novo AF accounts for 40% of all AF cases in ACS patients and is an unfavourable in-hospital prognostic factor. The occurrence of de novo AF during ACS should require special attention and caution in the treatment of these patients.

Association of inverted T wave during atrial fibrillation rhythm with subsequent cardiac events

OBJECTIVE

The clinical significance of ECG abnormalities during atrial fibrillation (AF) rhythm is poorly understood. The aim of the current study was to explore the impact of inverted T wave on cardiac prognosis in patients with AF.

METHODS

The current study enrolled 2709 patients with AF whose baseline ECG was available from a Japanese community-based prospective survey, the Fushimi AF Registry, and the impact of inverted T wave in baseline ECG at AF rhythm on the composite of cardiac death, myocardial infarction and hospitalisation due to heart failure was examined.

RESULTS

Intraventricular conduction delay, ST segment depression and inverted T wave were observed in 15.8%, 24.7% and 41.4% of baseline ECG with a mean heart rate of 94.7 beats per minute. The median follow-up duration was 5.0 years. The incidence rate of the composite cardiac endpoint was significantly higher in patients with inverted T wave than those without (5.8% vs 3.3% per patient-year, log-rank p<0.01). The higher risk associated with inverted T wave was consistent even for individual components of the composite cardiac endpoint. By multivariable analysis, inverted T wave was an independent predictor of the composite cardiac endpoint (HR 1.53, 95% CI 1.26 to 1.85, p<0.01). Inverted T wave was detected in 15.7% at anterior leads, 19.8% at inferior leads and 26.6% at lateral leads. The location of inverted T wave was not associated with risk of composite cardiac endpoint.

CONCLUSIONS

Inverted T wave was commonly observed in patients with AF and its presence during AF rhythm was associated with subsequent cardiac events.

Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy

BACKGROUND

Current guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known.

METHOD

We diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor. We compared mean, minimum, maximum HR between those with vs without SDB. In a pilot subanalysis of HCM patients with SDB who also underwent subsequent diagnostic polysomnography (PSG), we analyzed RR interval changes coinciding with obstructive sleep apnea and hypopnea episodes.

RESULTS

Of the 230 HCM patients included in this study (age 54 ± 16 years; 138 male; LVOT pressure gradient at rest 45 ± 39 mmHg), 115 (50%) patients had SDB. HCM patients with SDB were recorded to have higher mean HR (71 vs. 67 bpm; p = .002, adjusted p = .001), and this difference was most pronounced during night hours of 10 PM to 5 AM (61 vs. 67 bpm; p < .001). In the pilot analysis of the available PSG data, the release of obstructive sleep apneas and hypopneas coincided with fluctuation of HR.

CONCLUSIONS

SDB is independently associated with higher mean HR in patients with HCM, and this difference is most significant during sleep. Treatment of SDB, which is readily available, should be tested as a complementary modality to the currently recommended pharmacotherapy aimed at lowering HR in patients with symptomatic HCM.

Resting Heart Rate and In-Hospital Mortality in Acute Ischemic Stroke Patients With and Without Atrial Fibrillation

BACKGROUND

The prognostic role of resting heart rate (RHR) on mortality in acute ischemic stroke (AIS) patients including atrial fibrillation (AF) is unclear. This study evaluated the relationship between RHR and in-hospital mortality among all AIS patients with and without AF.Methods and Results:The study enrolled 3,447 AIS patients from December 2013 to May 2014 across 22 hospitals in Suzhou City. Patients were divided into 2 groups based on median baseline RHR (<76 and ≥76 beats/min). Cox proportional hazard regression models were used to estimate the effects of RHR on all-cause in-hospital mortality. During hospitalization, 124 patients (3.6%) died from all causes. A multivariable model adjusted for potential covariates showed that higher RHR (≥76 beats/min) was associated with an increase in the risk of in-hospital mortality among AIS patients (hazard ratio [HR] 1.63; 95% confidence interval [CI] 1.09-2.45; P=0.018). This relationship was consistent in a subgroup analysis of patients without AF (HR 2.39; 95% CI 1.29-4.45; P=0.006). However, there was no significant association between higher RHR and in-hospital mortality among patients with AF (P=0.654). Similar findings were confirmed in analyses with heart rate as a continuous variable.

CONCLUSIONS

Higher RHR at admission was independently associated with in-hospital mortality in AIS patients without AF.

Electrocardiographic predictors of mortality in patients after percutaneous coronary interventions - a nested case-control study

Background: The outcome of patients undergoing percutaneous coronary interventions (PCIs) varies considerably. Several ECG parameters have recently emerged (PQ interval, P-wave, T-peak-to-T-end interval, T-wave, T/R ratio, J-wave) beyond traditional markers (rhythm, QRS, Q-wave, QT interval, ST segment) and were attributed important prognostic value in the setting of coronary artery disease. The present study integrated for the first time these ECG parameters altogether with the aim to determine their role in predicting patients' outcome after a PCI. Methods: A total of 3342 patients were enrolled in the present study between 2009 and 2013. In a nested case-control design, 644 patients who died within a year post-PCI (cases) were matched 1:4 with patients alive at that particular date (controls). Results: Our data showed that only the presence of a longer QT interval (heart rate-corrected using Bazett formula) was associated with increased risk of death after adjusting for multiple clinical and angiographic risk factors (adjusted OR 1.07; 95%CI 1.01-1.12, p = .022). Conclusion: Our study emphasises the prognostic importance of the QT interval in identifying patients at increased risk of death during the first year after PCI. Clinical Trial Registration - URL: https://www.clinicaltrials.gov . Unique identifier: NCT02241291.

Admission Heart Rate Is a Determinant of Effectiveness of Beta-Blockers in Acute Myocardial Infarction Patients

BACKGROUND

Beta-blockers are standard therapy for acute myocardial infarction (AMI). However, despite current advances in the management of AMI, it remains unclear whether all AMI patients benefit from β-blockers. We investigated whether admission heart rate (HR) is a determinant of the effectiveness of β-blockers for AMI patients. Methods and Results: We enrolled 3,283 consecutive AMI patients who were admitted to 28 participating institutions in the Japanese Registry of Acute Myocardial Infarction Diagnosed by Universal Definition (J-MINUET) study. According to admission HR, we divided patients into 3 groups: bradycardia (HR <60 beats/min, n=444), normocardia (HR 60 to ≤100 beats/min, n=2,013), and tachycardia (HR >100 beats/min, n=342). The primary endpoint was major adverse cardiac events (MACE), including all-cause death, non-fatal MI, non-fatal stroke, heart failure (HF), and urgent revascularization for unstable angina, at 3-year follow-up. Beta-blocker at discharge was significantly associated with a lower risk of MACE in the tachycardia group (23.6% vs. 33.0%; P=0.033), but it did not affect rates of MACE in the normocardia group (17.8% vs. 18.4%; P=0.681). In the bradycardia group, β-blocker use at discharge was significantly associated with a higher risk of MACE (21.6% vs. 12.7%; P=0.026). Results were consistent for multivariable regression and stepwise multivariable regression.

CONCLUSIONS

Admission HR might determine the efficacy of β-blockers for current AMI patients.

Heart rate prediction of outcome in heart failure following myocardial infarction depend on heart rhythm status an analysis from the high-risk myocardial infarction database initiative

BACKGROUND

Heart rate has been reported to be associated with adverse outcome in heart failure (HF) and myocardial infarction (MI), but conflicting evidence exists regarding its impact in patients with associated atrial fibrillation (AF).

OBJECTIVES

We investigated the differential impact of heart rate on clinical outcomes according to the presence or absence of AF in patients with reduced systolic function and/or HF after MI.

METHODS

We studied the association of heart rate with outcome using Cox-models in a merged dataset (n=28,771) of four randomized trials (CAPRICORN, EPHESUS, OPTIMAAL, and VALIANT).

RESULTS

At baseline, 3736 (13%) patients had AF. We identified a significant interaction between AF and heart rate, and a decreasing effect of heart rate with time, heart rate being less associated with outcome after 1year of follow-up (both p for interaction <0.001). We report associations with outcome separately in patients with and without AF. In addition, as neutral associations with outcome after 1year were estimated after adjustment on confounding factors, only association for the first year follow-up were provided. 10-bpm increase in heart rate conferred increased risk for all-cause mortality (1.27 [1.21 to 1.33], p<0.0001), CV-mortality (1.28 [1.22 to 1.34], p<0.0001), and HF-hospitalisation (1.25 [1.19 to 1.31], p<0.0001) in patients without AF. In contrast, in patients with AF, the incremental risk for 10-bpm increase in heart rate was attenuated for all-cause (1.14 [1.06 to 1.23], p=0.0007), CV-mortality (1.12 [1.03 to 1.22], p=0.006), and HF-hospitalisation (1.16 [1.07 to 1.26], p=0.0006, p for interaction with AF <0.001 for all outcomes).

CONCLUSIONS

In patients with reduced systolic function and/or HF post-MI, higher heart rate predicts increased major cardiovascular events during the first year following MI in patients without AF. This association is markedly attenuated in subjects with AF.

A Review of the Relationship of Atrial Fibrillation and Acute Coronary Syndrome

Atrial fibrillation (AF) is the most common arrhythmia encountered by clinicians. Clinical decision-making focuses on reducing ischemic stroke risk in AF patients; however, AF is also associated with an increased risk of acute coronary syndromes (ACS). Patients with ACS and concurrent AF are less likely to receive appropriate therapies and more likely to experience adverse outcomes than ACS patients in sinus rhythm (SR). Clinicians may be able to stratify ACS patients at increased risk of AF development based on clinical characteristics. Evidence supporting specific therapeutic options for prevention of ACS in AF patients or for prevention of AF in ACS patients is limited, however there is some evidence of differing effects among oral anticoagulant regimens in these populations. Investigations of the relationship of AF with the full spectrum of ACS are not well described and should be the focus of future research.

Heart rate variables in the Vascular Quality Initiative are not reliable predictors of adverse cardiac outcomes or mortality after major elective vascular surgery

OBJECTIVE

Heart rate (HR) parameters are known indicators of cardiovascular complications after cardiac surgery, but there is little evidence of their role in predicting outcome after major vascular surgery. The purpose of this study was to determine whether arrival HR (AHR) and highest intraoperative HR are associated with mortality or major adverse cardiac events (MACEs) after elective vascular surgery in the Vascular Quality Initiative (VQI).

METHODS

Patients undergoing elective lower extremity bypass (LEB), aortofemoral bypass (AFB), and open abdominal aortic aneurysm (AAA) repair in the VQI were analyzed. MACE was defined as any postoperative myocardial infarction, dysrhythmia, or congestive heart failure. Controlled HR was defined as AHR <75 beats/min on operating room arrival. Delta HR (DHR) was defined as highest intraoperative HR - AHR. Procedure-specific MACE models were derived for risk stratification, and generalized estimating equations were used to account for clustering of center effects. HR, beta-blocker exposure, cardiac risk, and their interactions were explored to determine association with MACE or 30-day mortality. A Bonferroni correction with P < .004 was used to declare significance.

RESULTS

There were 13,291 patients reviewed (LEB, n = 8155 [62%]; AFB, n = 2629 [18%]; open AAA, n = 2629 [20%]). Rates of any preoperative beta-blocker exposure were as follows: LEB, 66.5% (n = 5412); AFB, 57% (n = 1342); and open AAA, 74.2% (n = 1949). AHR and DHR outcome association was variable across patients and procedures. AHR <75 beats/min was associated with increased postoperative myocardial infarction risk for LEB patients across all risk strata (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.03-1.9; P = .03), whereas AHR <75 beats/min was associated with decreased dysrhythmia risk (OR, 0.42; 95% CI, 0.28-0.63; P = .0001) and 30-day death (OR, 0.50; 95% CI, 0.33-0.77; P = .001) in patients at moderate and high cardiac risk. These HR associations disappeared in controlling for beta-blocker status. For AFB and open AAA repair patients, there was no significant association between AHR and MACE or 30-day mortality, irrespective or cardiac risk or beta-blocker status. DHR and extremes of highest intraoperative HR (>90 or 100 beats/min) were analyzed among all three operations, and no consistent associations with MACE or 30-day mortality were detected.

CONCLUSIONS

The VQI AHR and highest intraoperative HR variables are highly confounded by patient presentation, operative variables, and beta-blocker therapy. The discordance between cardiac risk and HR as well as the lack of consistent correlation to outcome makes them unreliable predictors. The VQI has elected to discontinue collecting AHR and highest intraoperative HR data, given insufficient evidence to suggest their importance as an outcome measure.