Sanjeev U. Nair

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms

BACKGROUND Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms. METHODS Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital. RESULTS Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P=0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P=0.04) and 5.65 (CI 1.66-19.23, P=0.006) respectively. CONCLUSION Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.

The impact of severe acidemia on neurologic outcome of cardiac arrest survivors undergoing therapeutic hypothermia

INTRODUCTION Therapeutic Hypothermia (TH) has become a standard of care in improving neurological outcomes in cardiac arrest (CA) survivors. Previous studies have defined severe acidemia as plasma pH<7.20. We investigated the influence of severe acidemia at the time of initiation of TH on neurological outcome in CA survivors. METHODS A retrospective analysis was performed on 196 consecutive CA survivors (out-of-hospital CA and in-hospital CA) who underwent TH with endovascular cooling between January 2007 and October 2012. Arterial blood gas drawn prior to initiation of TH was utilized to measure pH in all patients. Shockable and non-shockable CA patients were divided into two sub-groups based on pH (pH<7.2 and pH≥7.2). The primary end-point was measured using the Pittsburgh Cerebral Performance Category (CPC) scale prior to discharge from the hospital: good (CPC 1 and 2) and poor (CPC 3 to 5) neurologic outcome. RESULTS Sixty-two percent of shockable CA patients with pH≥7.20 had good neurological outcome as compared to 34% patients with pH<7.20. Shockable CA patients with pH≥7.20 were 3.3 times more likely to have better neurological outcome when compared to those with pH <7.20 [p=0.013, OR 3.3, 95% CI (1.28-8.45)]. In comparison, non-shockable CA patients with p≥7.20 did not have a significantly different neurological outcome as compared to those with pH<7.20 [p=0.97, OR 1.02, 95% CI (0.31-3.3)]. CONCLUSION Presence of severe acidemia at initiation of TH in shockable CA survivors is significantly associated with poor neurological outcomes. This effect was not observed in the non-shockable CA survivors.

Risk of new-onset atrial fibrillation in elderly patients with the overlap syndrome: a retrospective cohort study.

Objective Co-existence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) is referred to as overlap syndrome. Overlap patients have greater degree of hypoxia and pulmonary hypertension than patients with OSA or COPD alone. Studies showed that elderly patients with OSA alone do not have increased risk of atrial fibrillation (AF) but it is not known if overlap patients have higher risk of AF. To determine whether elderly patients with overlap syndrome have an increased risk of AF. Methods In this single center, community-based retrospective cohort analysis, data were collected on 2,873 patients > 65 years of age without AF, presenting in the year 2006. Patients were divided into OSA group (n = 60), COPD group (n = 416), overlap syndrome group (n = 28) and group with no OSA or COPD (n = 2369). The primary endpoint was incidence of new-onset AF over the following two years. Logistic regression was performed to adjust for heart failure (HF), coronary artery disease, hypertension (HTN), cerebrovascular disease, cardiac valve disorders, diabetes mellitus, hyperlipidemia, chronic kidney disease (CKD) and obesity. Results The incidence of AF was 10% in COPD group, 6% in OSA group and 21% in overlap syndrome group (P < 0.05). After adjusting for age, sex, HF, CKD, and HTN, patients with overlap syndrome demonstrated a significant association with new-onset AF (OR = 3.66, P = 0.007). HF, CKD and HTN were also significantly associated with new-onset AF (P < 0.05). Conclusion Among elderly patients, the presence of overlap syndrome is associated with a marked increase in risk of new-onset AF as compared to the presence of OSA or COPD alone.

The use of hypothermia therapy in cardiac arrest survivors.

The annual incidence of out-of-hospital cardiac arrests in the United States is ∼350,000-450,000 per year. The prognosis for cardiac arrest survivors remains extremely poor. Therapeutic hypothermia (TH) is the only therapy proven to improve survival and neurological outcome in these patients. This article discusses the pathophysiology of neurological injury in cardiac arrest survivors and states the presumed mechanisms by which TH mitigates brain injury in these patients. It reviews the contraindications to the use of this therapy, methods of cooling, and phases of TH and elaborates on the intensive care unit management of TH. The use of TH in ventricular fibrillation survivors has become the standard of care and continues to evolve in its application as an essential therapy in cardiac arrest patients.

The Role of Cardiac Nuclear Imaging in Heart Failure

The incidence of patients with congestive heart failure (CHF) is increasing in the U.S. and now constitutes over five million Americans [1]. Despite advances in treatment strategies, outcomes in patients with CHF are poor, especially in patients with left ventricular function less than 35% (normal 55–75%) [2]. Treatment plans for patients with heart failure are initially based upon whether the heart failure is due to ischemia (ischemic cardiomyopathy) or other causes (non-ischemic cardiomyopathy). This chapter will present the role of nuclear imaging in the evaluation and management of heart failure patients with regards to:

DOES THE OBESITY PARADOX EXIST IN DIABETIC PATIENTS WITH NO KNOWN CORONARY ARTERY DISEASE? RISK STRATIFICATION USING STRESS SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY MYOCARDIAL PERFUSION IMAGING

Methods: Data for 10, 429 consecutive patients undergoing stress SPECT myocardial perfusion imaging with no coronary artery disease were examined, of which 2,490 were DB. Interpretation was based on ASNC 17-segment model. Patients were classified as normal weight (NW), overweight (OW, BMI ≥ 25.0-29.9), or obese (BMI ≥30.0). Patients undergoing coronary revascularization ≤ 60 days after SPECT were excluded. Cardiac events included cardiac death and non-fatal myocardial infarction, and mean follow was 2.1± 3 years.