In-hospital versus out-of-hospital presentation of life-threatening ventricular arrhythmias predicts survival: results from the AVID Registry. Antiarrhythmics Versus Implantable Defibrillators

Comparison of central adjudication of outcomes and onsite outcome assessment on treatment effect estimates

BACKGROUND

Assessment of events by adjudication committees (ACs) is recommended in multicentre randomised controlled trials (RCTs). However, its usefulness has been questioned.

OBJECTIVES

The aim of this systematic review was to compare 1) treatment effect estimates of subjective clinical events assessed by onsite assessors versus by AC, and 2) treatment effect estimates according to the blinding status of the onsite assessor as well as the process used to select events to adjudicate.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, PsycINFO, CINAHL and Google Scholar (25 August 2015 as the last updated search date), using a combination of terms to retrieve RCTs with commonly used terms to describe ACs.

SELECTION CRITERIA

We included all reports of RCTs and the published RCTs included in reviews and meta-analyses that reported the same subjective outcome event assessed by both an onsite assessor and an AC.

DATA COLLECTION AND ANALYSIS

We extracted the odds ratio (OR) from onsite assessment and the corresponding OR from AC assessment and calculated the ratio of the odds ratios (ROR). A ratio of odds ratios < 1 indicated that onsite assessors generated larger effect estimates in favour of the experimental treatment than ACs.

MAIN RESULTS

Data from 47 RCTs (275,078 patients) were used in the meta-analysis. We excluded 11 RCTs because of incomplete outcome data to calculate the OR for onsite and AC assessments. On average, there was no difference in treatment effect estimates from onsite assessors and AC (combined ROR: 1.00, 95% confidence interval (CI) 0.97 to 1.04; I(2) = 0%, 47 RCTs). The combined ROR was 1.00 (95% CI 0.96 to 1.04; I(2) = 0%, 35 RCTs) when onsite assessors were blinded; 0.76 (95% CI 0.48 to 1.12, I(2) = 0%, two RCTs) when AC assessed events identified independently from unblinded onsite assessors; and 1.11 (95% CI 0.96 to 1.27, I(2) = 0%, 10 RCTs) when AC assessed events identified by unblinded onsite assessors. However, there was a statistically significant interaction between these subgroups (P = 0.03) AUTHORS' CONCLUSIONS: On average, treatment effect estimates for subjective outcome events assessed by onsite assessors did not differ from those assessed by ACs. Results of subgroup analysis showed an interaction according to the blinded status of onsite assessors and the process used to submit data to AC. These results suggest that the use of ACs might be most important when onsite assessors are not blinded and the risk of misclassification is high. Furthermore, research is needed to explore the impact of the different procedures used to select events to adjudicate.

Causes of death and re‐hospitalization in cardiogenic shock

BACKGROUND

In cardiogenic shock, causes of death usually are cardiac. However, a systemic inflammatory response syndrome may influence outcome.

METHODS

SHould we emergently revascularize Occluded Coronaries in cardiogenic shocK? (SHOCK) Trial patients (n = 302) were analyzed regarding cause of death and re-hospitalization.

RESULTS

Deaths (n = 180) occurred < or =30 days in 86% and >30 days in 14%. Known causes of death < or =30 days were cardiac in 88% (37% arrhythmic) and non-cardiac in 12% (29% septic). Non-cardiac deaths < or =30 days occurred later (206 [91,394] versus 41 [15,156] h, P<0.01) and were more frequently associated with signs of inflammation (43 versus 12%, P = 0.01) than cardiac deaths < or =30 days. Known causes of in-hospital death >30 days (n = 19) were cardiac in 58% and non-cardiac in 42%. Among deaths < or =30 days systemic vascular resistance index was higher (2,666+/-1,063 versus 2,090+/-731 dynes.sec.cm(-5) m(2), P = 0.05) than among deaths >30 days. Among the 116 survivors of the initial hospitalization with data available, 52 (45%) were readmitted, most of which due to heart failure (n = 22, 42%) and myocardial ischemia (n = 16, 31%).

CONCLUSIONS

In CS, early deaths < or =30 days are mainly cardiac. Non-cardiac deaths are associated with signs of inflammation. In survivors of the initial hospitalization, re-hospitalizations are due to heart failure and myocardial ischemia.

Cardiac arrest in the Emergency Department: a report from the National Registry of Cardiopulmonary Resuscitation

BACKGROUND

Little is known about cardiac arrests (CA) in the Emergency Department (ED). The objective of this study was to determine the characteristics of ED CAs.

METHODS

60,852 adult, in-patient CA events in the National Registry of Cardiopulmonary Resuscitation were included. Multiple regression analysis compared ED CA with those occurring in the ICU, telemetry, or general floors. Subgroup analysis examined traumatic vs. non-traumatic ED CA and ED CA occurring after a successful pre-hospital resuscitation (recurrent) vs. primary ED event.

RESULTS

In multivariate analysis, ED location predicted improved survival to discharge (OR 0.74, 95%CI [0.67-0.82]). ED CAs had higher survival to discharge rates (ED 22.2, ICU 15.5, Tele 19.8, Floor 10.8, p<0.0001), better cerebral performance category scores (ED 1.59, ICU 1.73, Tele 1.96, Floor 1.69, p<0.0001), and shorter post-event length of stays (ED 8.6, ICU 17.5, Tele 16.5, Floor 14.2 days, p<0.0001) than other locations. Recurrent ED CAs were less likely to survive to discharge (10.1% vs. 24.6%, p<0.0001) than primary events. Trauma-related ED CAs had a lower survival to discharge rate (7.5% vs. 23.8%, p<0.0001), were less likely to be caused by an arrhythmia (23.6% vs. 32.5%, p<0.0008), and more likely to be preceded by hypotension or shock (41.6% vs. 29.0%, p<0.0001) than non-trauma ED events.

CONCLUSIONS

ED CAs have unique characteristics, and better survival and neurologic outcomes compared to other hospital locations. Primary ED CAs have a better chance of survival to discharge than recurrent events. Traumatic ED CAs have worse outcomes than non-traumatic CA.

Limitations of ejection fraction for prediction of sudden death risk in patients with coronary artery disease: lessons from the MUSTT study

OBJECTIVES

We determined the contribution of multiple variables to predict arrhythmic death and total mortality risk in patients with coronary disease and left ventricular dysfunction. We then constructed an algorithm to predict risk of mortality and sudden death.

BACKGROUND

Many factors in addition to ejection fraction (EF) influence the prognosis of patients with coronary disease. However, there are few tools to use this information to guide clinical decisions.

METHODS

We evaluated the relationship between 25 variables and total mortality and arrhythmic death in 674 patients enrolled in the MUSTT (Multicenter Unsustained Tachycardia Trial) study that did not receive antiarrhythmic therapy. We then constructed risk-stratification algorithms to weight the prognostic impact of each variable on arrhythmic death and total mortality risk.

RESULTS

The variables having the greatest prognostic impact in multivariable analysis were functional class, history of heart failure, nonsustained ventricular tachycardia not related to bypass surgery, EF, age, left ventricular conduction abnormalities, inducible sustained ventricular tachycardia, enrollment as an inpatient, and atrial fibrillation. The model demonstrates that patients whose only risk factor is EF < or =30% have a predicted 2-year arrhythmic death risk <5%.

CONCLUSIONS

Multiple variables influence arrhythmic death and total mortality risk. Patients with EF < or =30% but no other risk factor have low predicted mortality risk. Patients with EF >30% and other risk factors may have higher mortality and a higher risk of sudden death than some patients with EF < or =30%. Thus, risk of sudden death in patients with coronary disease depends on multiple variables in addition to EF.

Pharmacotherapy considerations in advanced cardiac life support

Cardiac arrest and sudden cardiac death remain major causes of mortality. Early intervention has been facilitated by emergency medical response systems and the development of training programs in basic life support and advanced cardiac life support (ACLS). Despite the implementation of these programs, the likelihood of a meaningful outcome in many life-threatening situations remains poor. Pharmacotherapy plays a role in the management of patients with cardiac arrest, with new guidelines for ACLS available in 2005 providing recommendations for the role of specific drug therapies. Epinephrine continues as a recommended means to facilitate defibrillation in patients with pulseless ventricular tachycardia or ventricular fibrillation; vasopressin is an alternative. Amiodarone is the primary antiarrhythmic drug that has been shown to be effective for facilitation of defibrillation in patients with pulseless ventricular tachycardia or fibrillation and is also used for the management of atrial fibrillation and hemodynamically stable ventricular tachycardia. Epinephrine and atropine are the primary agents used for the management of asystole and pulseless electrical activity. Treatment of electrolyte abnormalities, severe hypotension, pulmonary embolism, acute ischemic stroke, and toxicologic emergencies are important components of ACLS management. Selection of the appropriate drug, dose, and timing and route of administration are among the many challenges faced in this setting. Pharmacists who are properly educated and trained regarding the use of pharmacotherapy for patients requiring ACLS can help maximize the likelihood of positive patient outcomes.

Comparing intravenous amiodarone or lidocaine, or both, outcomes for inpatients with pulseless ventricular arrhythmias*

OBJECTIVE

To compare survival rates of patients with in-hospital cardiac arrest due to pulseless ventricular tachycardia/ventricular fibrillation treated with lidocaine, amiodarone, or amiodarone plus lidocaine.

DESIGN

Multicenter retrospective medical record review.

SETTING

Three academic medical centers in the United States.

PATIENTS

Hospitalized adult patients who received amiodarone, lidocaine, or a combination for pulseless ventricular tachycardia/ventricular fibrillation between August 1, 2000, and July 31, 2002.

MEASUREMENTS AND MAIN RESULTS

Data were collected according to the Utstein style. In-hospital proportion of patients living at 24 hrs and discharge were analyzed using chi-square analysis. Of the 605 patient medical records reviewed, 194 met criteria for inclusion (n=79 for lidocaine, n=74 for amiodarone, n=41 for combination). Available data showed no difference in proportion of patients alive 24 hrs post-cardiac arrest (p=.39). Cox regression analysis indicated a decreased likelihood of survival in patients with pulseless ventricular tachycardia/ventricular fibrillation as an initial rhythm as compared with those who presented with bradycardia followed by pulseless ventricular tachycardia/ventricular fibrillation and in those patients who received amiodarone as compared with lidocaine. However, only 14 patients (25%) in the amiodarone group received the recommended initial 300-mg intravenous bolus, and amiodarone was administered an average of 8 mins later in the code compared with lidocaine (p<.001).

CONCLUSIONS

These results generate the hypothesis that inpatients with cardiac arrest may have different benefits from lidocaine and amiodarone than previously demonstrated. Inadequate dosing and later administration of amiodarone in the code were two confounding factors in this study. Prospective studies evaluating these agents are warranted.

Identifying the high risk patient with coronary artery disease--is ejection fraction all you need?

Although the total number of deaths resulting from cardiovascular disease has decreased in the United States, the percentage of cardiac deaths that occur suddenly has increased. Over the past 10 years, a number of randomized clinical trials have evaluated the ability of antiarrhythmic therapy to reduce mortality in patients in patients with chronic coronary disease and abnormal left ventricular function that had not yet developed spontaneous sustained VT or VF. A majority of these trials have demonstrated that the implantable cardioverter-defibrillator (ICD) can reduce mortality compared to pharmacologic antiarrhythmic therapy, or no specific antiarrhythmic therapy. While, reduced left ventricular ejection fraction (EF) has been a major determinant for entry into these studies, in all but one case, it was not the sole entry requirement. These studies have demonstrated that a number of factors have prognostic significance, and therefore impact efficacy of the ICD. None of these studies was designed to evaluate the relative efficacy of various risk factors. Therefore, we lack adequate information today to determine the most cost-effective manner in which to assign use of ICDs for primary prevention. This article reviews the potential for using EF alone as a risk factor, as well as the efficacy of other variables for risk stratification.

Mode of death in heart failure: findings from the ATLAS trial

OBJECTIVE

To investigate markers that predict modes of death in patients with chronic heart failure.

DESIGN

Randomised, double blind, three period, comparative, parallel group study (ATLAS, assessment of treatment with lisinopril and survival).

PATIENTS

3164 patients with mild, moderate, or severe chronic heart failure (New York Heart Association functional class II-IV).

INTERVENTIONS

High dose (32.5 or 35 mg) or low dose (2.5 or 5 mg) lisinopril once daily for a median of 46 months.

MAIN OUTCOME MEASURES

All cause mortality, cardiovascular mortality, sudden death, and chronic heart failure death related to prognostic factors using competing risks analysis. Mode of death was classified by trialists and by an independent end point committee.

RESULTS

Age, male sex, pre-existing ischaemic heart disease, increasing heart rate, creatinine concentration, and certain drugs taken at randomisation were markers of increased risk of all cause mortality and cardiovascular death. There were risk markers for sudden death that were different from the risk markers for death from chronic heart failure. Low systolic blood pressure at baseline, raised creatinine, reduced serum sodium or haemoglobin, and increased heart rate were associated with chronic heart failure death. Use of beta blockers or antiarrhythmic agents (mainly amiodarone) was associated with a reduced risk of sudden death, whereas long acting nitrates and previous use of angiotensin converting enzyme inhibitors were markers for increased risk.

CONCLUSIONS

The use of competing risks analysis on the data from the ATLAS study has identified variables associated with certain modes of death in heart failure patients. This approach to analysing outcomes may make it possible to predict which patients might benefit most from particular therapeutic interventions.

Implantable cardioverter defibrillators in heart failure

Implantable cardioverter defibrillators provide effective and reliable treatment of spontaneous VT and VF. These devices can be expected to decrease the risk for arrhythmic death in patients with heart failure but do not improve overall survival when death from severe pump dysfunction is imminent. Appropriate patient selection is a major aspect of arrhythmia management. Future devices will incorporate features that have the potential to reduce atrial arrhythmias, improve ventricular function, monitor hemodynamics, and prevent sudden arrhythmic death.

Differences in inducibility and prognosis of in-hospital versus out-of-hospital identified nonsustained ventricular tachycardia in patients with coronary artery disease: clinical and trial design implications

OBJECTIVES

The goal of this study was to describe the influence of the clinical setting (in-hospital vs. out-of-hospital) in which nonsustained ventricular tachycardia (NSVT) is discovered on the rate of inducibility of sustained ventricular tachycardia (VT), arrhythmic events and survival in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction.

BACKGROUND

In-hospital presentation of sustained VT is independently associated with lower long-term overall survival. The impact of the clinical setting in which NSVT is documented is unknown.

METHODS

In the Multicenter Unsustained Tachycardia Trial (MUSTT), designed to assess the benefit of randomized antiarrhythmic therapy guided by electrophysiologic testing in patients with asymptomatic NSVT, CAD and LV dysfunction, eligible patients were enrolled irrespective of the setting in which the index arrhythmia was discovered. In this retrospective analysis, we compared the rate of VT inducibility and outcome of MUSTT-enrolled patients with in-hospital versus out-of-hospital presentation of NSVT.

RESULTS

Monomorphic sustained VT was induced in 35% and 28% of the patients whose index NSVT occurred in-hospital and out-of-hospital, respectively (adjusted p = 0.006). Cardiac arrest or death due to arrhythmia at two- and five-year follow-ups were 14% and 28% for untreated patients with in-hospital-identified NSVT and 11% and 21% for the out-of-hospital group (adjusted p = 0.10). Overall mortality rates at two- and five-year follow-ups were 24% and 48% for inpatients and 18% and 38% for outpatients (adjusted p = 0.018). In patients randomized to antiarrhythmic therapy, there was no significant interaction between patient status (in-hospital vs. out-of-hospital) and treatment impact on the rates of total mortality (p = 0.98) and arrhythmic events (p = 0.08).

CONCLUSIONS

In patients with CAD and impaired LV function, asymptomatic NSVT identified in-hospital, compared with that identified out-of-hospital, is associated with a higher rate of induction of sustained VT and overall mortality. Therefore, in similar patients, the clinical setting in which NSVT is discovered should be taken into account when formulating patient risk, treatment and clinical trial design.