Cardiac arrest survivors with moderate elevated body mass index may have a better neurological outcome: A cohort study

Influence of patient body weight on the probability of return of spontaneous circulation following out-of-hospital cardiac arrest: an exploratory analysis

Introduction

In addition to key interventions, including bystander CPR and defibrillation, successful resuscitation of out-of-hospital cardiac arrest (OHCA) is also associated with several patient-level factors, including a shockable presenting rhythm, younger age, Caucasian race and female sex. An additional patient-level factor that may influence outcomes is patient weight, yet this attribute has not been extensively studied within the context of OHCA, despite globally increasing obesity rates.

Objective

To assess the relationship between patient weight and return of spontaneous circulation (ROSC) during OHCA.

Methods

This retrospective study included adult patients from a national emergency medical services (EMS) patient record, with witnessed, non-traumatic OHCA prior to EMS arrival from January to December 2020. Logistic regression was used to evaluate the relationship between patient weight and ROSC.

Results

Complete records were available for 9096 patients, of which 64.3% were males and 25.3% were ethnic minorities. The mean age of the participants was 65.01 years (SD = 15.8), with a mean weight of 93.52 kg (SD = 31.5). Altogether, 81.8% of arrests were of presumed cardiac aetiology and 30.3% presented with a shockable rhythm. Bystander CPR and automated external defibrillator (AED) shock were performed in 30.6% and 7.3% of cases, respectively, and 44.0% experienced ROSC. ROSC was less likely with patient weight >100 kg (OR = 0.709, p <0.001), male sex (OR = 0.782, p <0.001), and increasing age and EMS response time (OR = 0.994 per year, p <0.001 and OR = 0.970 per minute, p <0.001, respectively). Patients with shockable rhythms were more likely to achieve ROSC (OR = 1.790, p <0.001), as were patients receiving bystander CPR (OR = 1.170, p <0.001) and defibrillation prior to EMS arrival (OR = 1.658, p <0.001). Although the mean first adrenaline dose (mg/kg) followed a downward trend due to its non-weight-based dosing scheme, the mean total adrenaline dose administered to achieve ROSC demonstrated an upward linear trend of 0.05 mg for every 5 kg of body weight.

Conclusions

Patient weight was negatively associated with ROSC and positively associated with the total adrenaline dose required to attain ROSC.

Association of temporal change in body mass index with sudden cardiac arrest in diabetes mellitus

BACKGROUND

Underweight imposes significant burden on cardiovascular outcomes in patients with diabetes mellitus. However, less is known about the impact of serial change in body weight status measured as body mass index (BMI) on the risk of sudden cardiac arrest (SCA). This study investigated the association between SCA and temporal change in BMI among patients with diabetes mellitus.

METHODS

Based on Korean National Health Insurance Service database, participants with diabetes mellitus who underwent health examination between 2009 and 2012 and had prior health examination data (four years ago, 2005-2008) were retrospectively analyzed. BMI was measured at baseline (2005-2008) and 4-year follow-up health examination (2009-2012). Patients were classified in four groups according to the body weight status and its temporal change: sustained non-underweight, sustained underweight, previous underweight, and newly developed underweight. Primary outcome was defined as occurrence of SCA.

RESULTS

A total of 1,355,746 patients with diabetes mellitus were included for analysis, and SCA occurred in 12,554 cases. SCA was most common in newly developed underweight (incidence rate = 4.45 per 1,000 person-years), followed by sustained underweight (incidence rate = 3.90), previous underweight (incidence rate = 3.03), and sustained non-underweight (incidence rate = 1.34). Adjustment of covariates resulted highest risk of SCA in sustained underweight (adjusted hazard ratio = 2.60, 95% confidence interval [2.25-3.00], sustained non-underweight as a reference), followed by newly developed underweight (2.42, [2.15-2.74]), and previous underweight (2.12, [1.77-2.53]).

CONCLUSIONS

In diabetes mellitus, sustained underweight as well as decrease in body weight during 4-year follow-up imposes substantial risk on SCA. Recovery from underweight over time had relatively lower, but yet increased risk of SCA. Both underweight and dynamic decrease in BMI can be associated with increased risk of SCA.

Impact of Body Mass Index on Cardiac Arrest Outcomes: A Systematic Review and Meta-Analysis

The influence of an individual's body mass index (BMI) on cardiac arrest outcomes remains uncertain. The aim of this study is to evaluate the impact of BMI categories (underweight, normal BMI, overweight, and obese) on mortality and neurological outcomes in patients experiencing cardiac arrest. We comprehensively searched standard electronic databases (PubMed, EMBASE, and Scopus) for relevant observational studies published in peer-reviewed journals written in English. We calculated pooled effect estimates using random-effects models and reported them as odds ratios (ORs) with 95% confidence intervals (CIs). We included 20 studies in our meta-analysis. Individuals with normal BMIs and those who were underweight had similar risks of in-hospital mortality (OR, 1.20; 95% CI, 0.90-1.60), mortality within 6 months of discharge (OR, 0.92; 95% CI, 0.59-1.42), mortality after the 1-year follow-up (OR, 2.42; 95% CI, 0.96-6.08), and odds of favorable neurological outcomes at hospital discharge (OR, 0.86; 95% CI, 0.53-1.39) and at the 6-month follow-up (OR, 0.73; 95% CI, 0.47-1.13). The risks of in-hospital mortality and mortality within 6 months of discharge in overweight and obese individuals were similar to those in individuals with normal BMIs. However, overweight (OR, 0.57; 95% CI, 0.35-0.92) and obese individuals (OR, 0.67; 95% CI, 0.51-0.89) had lower risks of mortality after their 1-year follow-ups. For overweight and obese subjects, the reduced risk of mortality after the 1 year of follow-up was noted only for those with in-hospital cardiac arrest and not for those with out-of-hospital cardiac arrest. The odds of favorable neurological outcomes in both overweight and obese individuals were similar to those with normal BMIs. BMI does not significantly impact short-term mortality or neurological outcomes. Overweight and obese individuals appear to have a lower risk of long-term mortality, but this differed by the place of arrest and needs to be confirmed by others.

The Impact Of BMI On Arrest Characteristics and Survival of Patients with Out-Of-Hospital Cardiac Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation

AIM

To assess the impact of body mass index (BMI) on survival to hospital discharge of patients presenting with refractory ventricular fibrillation treated with extracorporeal cardiopulmonary resuscitation. We hypothesize that due to limitations in pre-hospital care delivery, people with high BMI have worse survival after prolonged resuscitation and ECPR.

METHODS

This study is a retrospective single-centre study that included patients suffering refractory VT/VF OHCA from December 2015 to October 2021 and had a BMI calculated at hospital admission. We compared the baseline characteristics and survival between patients with obesity (>30 kg/m²) and those without (≤30kg/m²).

RESULTS

Two-hundred eighty-three patients were included in this study, and two-hundred twenty-four required mechanical support with veno-arterial extracorporeal cardiopulmonary membrane oxygenation (VA ECMO). Patients with BMI >30 (n = 133) had significantly prolonged CPR duration compared to their peers with BMI ≤30kg/m² (n = 150) and were significantly more likely to require support with VA ECMO (85.7% vs 73.3%, p = 0.015). Survival to hospital discharge was significantly higher in patients with BMI≤30 kg/m² (48% vs. 29.3%, p <0.001). BMI was an independent predictor of mortality in a multivariable logistic regression analysis. The four-year mortality rate was low and not significantly different between the two groups (p=0.32).

CONCLUSION

ECPR yields clinically meaningful long-term survival in patients with BMI>30kg/m². However, the resuscitation time is significantly prolonged, and the overall survival significantly lower compared to patients with BMI≤30 kg/m². ECPR should, therefore, not be withheld for this population, but faster transport to an ECMO capable centre is mandated to improve survival to hospital discharge.

The Impact of Obesity on Sudden Cardiac Death Risk

PURPOSE OF REVIEW

We aimed to describe the epidemiology of sudden cardiac death (SCD) in the obese, elaborating on the potential pathophysiological mechanisms linking obesity, SCD, and the outcomes in SCD survivors, as well as looking into the intriguing "obesity paradox" in these patients.

RECENT FINDINGS

Several studies show increased mortality in patients with BMI > 30 kg/m² admitted to the hospital following SCD. At the same time, other studies have implied that the "obesity paradox," described in various cardiovascular conditions, applies to patients admitted after SCD, showing lower mortality in the obese compared to normal weight and underweight patients. We found a significant body of evidence to support that while obesity increases the risk for SCD, the outcomes of obese patients post SCD are better. These findings should not be interpreted as supporting weight gain, as it is always better to prevent the "disaster" from happening than to improve your chances of surviving it. Obesity is shown to be significantly associated with increased risk for SCD; however, there is a growing body of evidence, supporting the "obesity paradox" in the survival of SCD victims. Prospectively, well-designed studies are needed to confirm these findings.

Emergencies in obese patients: a narrative review

Obesity is associated to an increased risk of morbidity and mortality due to respiratory, cardiovascular, metabolic, and neoplastic diseases. The aim of this narrative review is to assess the physio-pathological characteristics of obese patients and how they influence the clinical approach during different emergency settings, including cardiopulmonary resuscitation. A literature search for published manuscripts regarding emergency and obesity across MEDLINE, EMBASE, and Cochrane Central was performed including records till January 1, 2021. Increasing incidence of obesity causes growth in emergency maneuvers dealing with airway management, vascular accesses, and drug treatment due to both pharmacokinetic and pharmacodynamic alterations. Furthermore, instrumental diagnostics and in/out-hospital transport may represent further pitfalls. Therefore, people with severe obesity may be seriously disadvantaged in emergency health care settings, and this condition is enhanced during the COVID-19 pandemic, when obesity was stated as one of the most frequent comorbidity. Emergency in critical obese patients turns out to be an intellectual, procedural, and technical challenge. Organization and anticipation based on the understanding of the physiopathology related to obesity are very important for the physician to be mentally and physically ready to face the associated issues.

Association between Body Mass Index and Outcomes in Patients with Return of Spontaneous Circulation after Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

Increased body mass index (BMI) is a risk factor for cardiovascular disease, stroke, and metabolic diseases. A high BMI may affect outcomes of post-cardiac arrest patients, but the association remains debatable. We aimed to determine the association between BMI and outcomes in patients with return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA). A systematic literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library. Studies that included patients who presented ROSC after OHCA, had a recorded BMI, and were assessed for neurological outcomes and in-hospital mortality were included. To assess the risk of bias of each included study, we employed the Risk of Bias Assessment Tool for Non-randomized Studies. We assessed 2427 patients from six studies. Neurological outcomes were significantly poorer in underweight patients (risk ratio (RR) = 1.21; 95% confidence interval (CI) = 1.07-1.37; p = 0.002; I2 = 51%) than in normal-weight patients. Additionally, in-hospital mortality rate was significantly higher in underweight patients (RR = 1.35; 95% CI = 1.14-1.60; p<0.001; I2 = 21%) and in obese patients (RR = 1.25; 95% CI = 1.12-1.39; p<0.001; I2 = 0%) than in normal-weight patients. Poor neurological outcome is associated with underweight, and low survival rate is associated with underweight and obesity in patients with ROSC after OHCA.

Association between body mass index and clinical outcomes in out-of-hospital cardiac arrest survivors treated with targeted temperature management

BACKGROUND

To determine the impact of body mass index (BMI) on clinical outcomes in out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM).

METHODS

We conducted a retrospective cohort study of 261 adult OHCA survivors who received complete TTM between January 2011 and December 2018 using data from the Research Patient Database Registry of Partners HealthCare system in Boston. Patients were categorized as underweight (BMI < 18.5 kg/m2), normal weight (BMI = 18.5-24.9 kg/m2), overweight (BMI = 25-29.9 kg/m2), and obese (BMI ≥ 30 kg/m2), according to the World Health Organization classification.

RESULTS

The average BMI was 28.9 ± 7.1 kg/m2. Patients with a higher BMI had higher rates of hypertension and diabetes mellitus, and were more likely to be witnessed on collapse. Patients with lower BMI levels had higher sequential organ failure assessment (SOFA) scores, blood urea nitrogen values, and mild thrombocytopenia rates (platelet count <150 K/μL) after the TTM treatment. The survival to discharge and favorable neurological outcome at discharge were reported in 117 (44.8%) and 76 (29.1%) patients, respectively. The survival at discharge, favorable neurologic outcomes at discharge, length of hospital admission, and the occurrence of acute kidney injury did not significantly differ between the BMI subgroups. In logistic regression model, BMI was not an independent predictor for survival at discharge (adjusted odds ratio 0.945, 95% CI 0.883-1.012, p = 0.108) nor for the favorable neurologic outcome at discharge (adjusted odds ratio 1.022, 95% CI 0.955-1.093, p = 0.528).

CONCLUSION

In OHCA patients treated with TTM, there was no significant difference across BMI subgroups for survival or favorable neurologic outcome at discharge.

Association between the body mass index and outcomes of patients resuscitated from out-of-hospital cardiac arrest: a prospective multicentre registry study

Background

The effects of the body mass index (BMI) on outcomes of patients resuscitated from cardiac arrest are controversial. Therefore, the current study investigated the association between the BMI and the favourable neurologic outcomes and survival to discharge of patients resuscitated from out-of-hospital cardiac arrest (OHCA).

Methods

This multicentre, prospective, nationwide OHCA registry-based study was conducted using data from the Korean Cardiac Arrest Resuscitation Consortium (KoCARC). We enrolled hospitals willing to collect patient height and weight and included patients who survived to the hospital between October 2015 and June 2018. The included patients were categorised into the underweight (< 18.5 kg/m²), normal weight (≥18.5 to < 25 kg/m²), overweight (≥25 to < 30 kg/m²), and obese groups (≥30 kg/m²) according to the BMI per the World Health Organization (WHO) criteria. The primary outcome was a favourable neurologic outcome; the secondary outcome was survival to discharge. Univariate and multivariate analyses were performed to investigate the association between BMI and outcomes.

Results

Nine hospitals were enrolled; finally, 605 patients were included in our analysis and categorised per the WHO BMI classification. Favourable neurologic outcomes were less frequent in the underweight BMI group than in the other groups (p = 0.002); survival to discharge was not significantly different among the BMI groups (p = 0.110). However, the BMI classification was not associated with favourable neurologic outcomes or survival to discharge after adjustment in the multivariate model.

Conclusion

The BMI was not independently associated with favourable neurologic and survival outcomes of patients surviving from OHCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00837-x.

Obese cardiogenic arrest survivors with significant coronary artery disease had worse in-hospital mortality and neurological outcomes

Cardiogenic arrest is the major cause of sudden cardiac arrest (SCA), accounting for 20% of all deaths annually. The association between obesity and outcomes in cardiac arrest survivors is debatable. However, the effect of obesity on the prognosis of patients with significant coronary artery disease (CAD) successfully resuscitated from cardiogenic arrest is unclear. Thus, the association between body mass index (BMI) and outcomes in cardiogenic arrest survivors with significant CAD was investigated. This multicentre retrospective cohort study recruited 201 patients from January 2011 to September 2017. The eligible cardiogenic arrest survivors were non-traumatic adults who had undergone emergency coronary angiography after sustained return of spontaneous circulation and had significant coronary artery stenosis. BMI was used to classify the patients into underweight, normal-weight, overweight, and obese groups (< 18.5, 18.5–24.9, 25.0–29.9, and ≥ 30 kg/m²; n = 9, 87, 72, and 33, respectively). In-hospital mortality and unsatisfactory neurological outcomes (cerebral performance scale scores = 3–5) were compared among the groups. The obese group presented higher in-hospital mortality and unsatisfactory neurological outcome risks than the normal-weight group (in-hospital mortality: adjusted hazard ratio = 4.27, 95% confidence interval (CI) 1.87–12.04, P = 0.008; unsatisfactory neurological outcomes: adjusted odds ratio = 3.33, 95% CI 1.42–8.78, P = 0.009). Subgroup analysis showed significantly higher in-hospital mortality in the obese patients than in the others in each clinical characteristic. In cardiogenic arrest survivors with significant CAD, obesity was associated with high risks of mortality and unsatisfactory neurological recovery.

Plasma Adipokines in Patients Resuscitated from Cardiac Arrest: Difference of Visfatin between Survivors and Nonsurvivors

Background

Adipokines are a group of cytokines or peptides secreted by adipose tissue to exert numerous biological functions. In the present study, we measured the plasma levels of four adipokines (adiponectin, leptin, fatty acid-binding protein 4 (FABP4), and visfatin) in cardiac arrest patients following return of spontaneous circulation (ROSC).

Methods

Totally, 21 patients who experienced cardiac arrest and successful ROSC with expected survival of at least 48 hours (from January 2016 to December 2017) were consecutively enrolled into this prospective observational clinical study. Of the 21 enrolled patients, ten survived, and other eleven died between 2 days and 6 months post ROSC. Venous blood was drawn at three time points: baseline (<1 hour post ROSC), 2 days post ROSC, and 7 days post ROSC. Plasma concentrations of adiponectin, leptin, FABP4, and visfatin were determined using commercial enzyme-linked immunosorbent assays.

Results

The plasma visfatin levels at 2 or 7 days post ROSC increased significantly compared with the baseline (P < 0.01), while plasma levels of adiponectin, leptin, and FABP4 did not change. Moreover, plasma visfatin levels in survivors at 2 or 7 days post ROSC were higher than those in nonsurvivors (P < 0.01). Plasma visfatin levels at 2 or 7 days post ROSC were negatively correlated with Acute Physiology and Chronic Health Evaluation (APACHE) II score and time to ROSC. Moreover, receiver operating characteristic curve analysis showed that the plasma visfatin levels at 2 or 7 days post ROSC were good predictors for survival of the patients.

Conclusion

Elevated plasma visfatin levels may be a marker for better outcome of cardiac arrest patients post ROSC.

Obesity is associated with poor prognosis in cardiogenic arrest survivors receiving coronary angiography

BACKGROUND

The role of body mass index (BMI) in clinical outcomes in patients resuscitated from cardiac arrest (CA) has recently drawn attention. We evaluated the effect of BMI on the prognosis of patients successfully resuscitated from cardiogenic arrest.

METHODS

This retrospective cohort study included 273 non-traumatic adult cardiogenic arrest survivors receiving coronary angiography after return of spontaneous circulation in three hospitals from January 2011 to September 2017. These patients were classified as underweight, normal-weight, overweight, and obese, based on BMI (<18.5; 18.5-24.9; 25.0-29.9; and ≥30 kg/m², respectively). In-hospital mortality and poor neurological outcomes were compared among groups.

RESULTS

The obese group had significantly higher rates of in-hospital mortality and poor neurological outcomes (cerebral performance scale = 3-5) than did the other groups (for underweight, normal-weight, overweight, and obese groups, in-hospital mortality rates were 38.5%, 29.8%, 39.0%, and 64.1%, respectively, p = 0.002; poor neurological outcomes were 53.9%, 43.8%, 47.0%, and 71.8%, respectively, p = 0.02). The obese group exhibited higher risks of in-hospital mortality and poor neurological outcomes than did the normal-weight group (in-hospital mortality: adjusted hazard ratio (aHR) = 5.21, 95% confidence interval (CI) 2.16-10.32, p < 0.001; poor neurological outcomes: aHR = 3.77, 95% CI 1.69-8.36, p = 0.002).

CONCLUSION

Obesity was associated with higher risks of in-hospital mortality and poor neurological recovery.

The effects of thoracic cage dimension and chest subcutaneous adipose tissue on outcomes of adults with in-hospital cardiac arrest: A retrospective study

BACKGROUND

The associations between thoracic cage dimension, chest subcutaneous adipose tissue (SAT) depth and outcomes of adults with in-hospital cardiac arrest (IHCA) remain unknown.

METHODS

We retrospectively evaluated IHCA patients between January 2016 and October 2017. The thoracic cage transverse diameter, internal AP diameter, cross-sectional area, anterior and posterior SAT depths were measured in computed-tomography (CT) images. Using logistic regression models, we determined the adjusted associations between thoracic cage dimension, SAT depths and the prognosis for IHCA. The primary outcome was sustained return of spontaneous circulation (ROSC) and the secondary outcome was survival to hospital discharge.

RESULTS

Among 423 IHCA patients, 258 patients achieved ROSC and 70 survived to discharge. Smaller cross-sectional area and posterior SAT depth were significantly related to ROSC. Smaller posterior SAT depth was associated with ROSC. After multivariate adjustment, the smaller cross-sectional area was independently associated with ROSC (Odds ratio [OR] 0.99, 95% confidence interval [95%CI] 0.99-1.00; p = 0.008) and survival to discharge (OR 0.99, 95%CI 0.98-1.00; p = 0.024), and the smaller posterior SAT depth was independently related to ROSC (OR 0.65, 95%CI 0.44-0.96; p = 0.030), whereas no relation to survival to discharge was found.

CONCLUSIONS

In adults with IHCA, the smaller thoracic cage dimension and posterior SAT depth are associated with better survival. An adjustable compression depth based on the thoracic cage dimension might be better than the "one-size-fits-all" compression depth for resuscitating CA patients. In addition, physicians should pay extra attention to compression efficacy when resuscitating obese patients.

Associations between body size and outcomes of adult in-hospital cardiac arrest: A retrospective cohort study

AIM

Animal studies have demonstrated that hemodynamic-directed cardiopulmonary resuscitation (CPR) improves outcomes following cardiac arrest compared with the "one-size-fits-all" algorithm. We investigated whether body size of patients is correlated with outcomes of in-hospital cardiac arrest (IHCA).

METHODS

A retrospective study in a single centre was conducted. Adult patients experiencing IHCA between 2006 and 2015 were screened. Body mass index (BMI) was calculated using body weight and height measured at hospital admission. Thoracic anteroposterior diameter (APD) was measured by analysing computed tomography images. Multivariate logistic regression analysis was used to study the associations between independent variables and outcomes. Generalised additive models were used to identify cut-off points for continuous variables.

RESULTS

A total of 766 patients were included, and 60.4% were male. Their mean age was 62.8 years. Mean BMI was 22.9 kg/m², and the mean thoracic APD was 21.4 cm. BMI > 23.2 kg/m² was inversely associated with a favourable neurological outcome (odds ratio [OR]: 0.30, 95% confidence interval [CI]: 0.13-0.68; p-value = 0.004), while thoracic APD was not. When the interaction term was analysed, BMI > 23.2 (kg/m²) × thoracic APD > 18.5 (cm) was inversely associated with both a favourable neurological outcome (OR: 0.33, 95% CI: 0.16-0.69; p-value = 0.003) and survival to hospital discharge (OR: 0.46, 95% CI: 0.26-0.81; p-value = 0.007).

CONCLUSION

Higher BMI and thoracic APD was correlated with worse outcomes following IHCA. For those patients, it might be better to perform CPR under guidance of physiological parameters rather than a "one-size-fits-all" resuscitation algorithm to improve outcomes.

Association of body mass index with clinical outcomes for in-hospital cardiac arrest adult patients following extracorporeal cardiopulmonary resuscitation

BACKGROUND

Obesity might be associated with disturbance of cannulation in situation of extracorporeal cardiopulmonary resuscitation (ECPR). However, limited data are available on obesity in the setting of ECPR. Therefore, we investigated the association between body mass index (BMI) and clinical outcome in patients underwent ECPR.

METHODS

From January 2004 to December 2013, in-hospital cardiac arrest patients who had ECPR were enrolled from a single-center registry. We divided patients into four group according to BMI defined with the WHO classification (underweight, BMI < 18.5, n = 14; normal weight, BMI = 18.5-24.9, n = 118; overweight, BMI = 25.0-29.9, n = 53; obese, BMI ≥ 30, n = 15). The primary outcome was survival to hospital discharge.

RESULTS

Analysis was carried out for a total of 200 adult patients (39.5% females). Their median BMI was 23.20 (interquartile range, 20.93-25.80). The rate of survival to hospital discharge was 31.0%. There was no significant difference in survival to hospital discharge among the four groups (underweight, 35.7%; normal, 31.4%; overweight, 30.2%; obese, 26.7%, p = 0.958). Neurologic outcomes (p = 0.85) and procedural complications (p = 0.40) were not significantly different among the four groups either. SOFA score, initial arrest rhythm, and CPR to extracorporeal membrane oxygenation (ECMO) pump on time were significant predictors for survival to discharge, but not BMI.

CONCLUSION

BMI was not associated with in-hospital mortality who underwent ECPR. Neurologic outcomes at discharge or procedural complications following ECPR were not related with BMI either.

Outcomes of In-Hospital Cardiopulmonary Resuscitation in Morbidly Obese Patients

OBJECTIVES

This study sought to assess the impact of morbid obesity on outcomes in patients with in-hospital cardiac arrest (IHCA).

BACKGROUND

Obesity is associated with increased risk of out-of-hospital cardiac arrest; however, little is known about survival of morbidly obese patients with IHCA.

METHODS

Using the Nationwide Inpatient Sample database from 2001 to 2008, we identified adult patients undergoing resuscitation for IHCA, including those with morbid obesity (body mass index ≥40 kg/m²) by using International Classification of Diseases 9th edition codes and clinical outcomes. Outcomes including in-hospital mortality, length of stay, and discharge dispositions were identified. Logistic regression model was used to examine the independent association of morbid obesity with mortality.

RESULTS

Of 1,293,071 IHCA cases, 27,469 cases (2.1%) were morbidly obese. The overall mortality was significantly higher for the morbidly obese group than for the nonobese group experiencing in-hospital non-ventricular fibrillation (non-VF) (77% vs. 73%, respectively; p = 0.006) or VF (65% vs. 58%, respectively; p = 0.01) arrest particularly if cardiac arrest happened late (>7 days) after hospitalization. Discharge to home was significantly lower in the morbidly obese group (21% vs. 31%, respectively; p = 0.04). After we adjusted for baseline variables, morbid obesity remained an independent predictor of increased mortality. Other independent predictors of mortality were age and severe sepsis for non-VF and VF group and venous thromboembolism, cirrhosis, stroke, malignancy, and rheumatologic conditions for non-VF group.

CONCLUSIONS

The overall mortality of morbidly obese patients after IHCA is worse than that for nonobese patients, especially if IHCA occurs after 7 days of hospitalization and survivors are more likely to be transferred to a skilled nursing facility.

Influence of body mass index on the prognosis of patients successfully resuscitated from out-of-hospital cardiac arrest treated by therapeutic hypothermia

BACKGROUND

Obesity prevalence has dramatically increased over recent years and is associated with cardiovascular diseases, but data are lacking on its prognostic impact in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

Data of all consecutive OHCA patients admitted in two cardiac arrest centers from Paris and suburbs between 2005 and 2012 were prospectively collected. Patients treated by therapeutic hypothermia (TH) were included in the analysis. Logistic and Cox regression analyses were used to quantify the association between body mass index (BMI) at hospital admission and day-30 and 1-year mortality respectively.

RESULTS

818 patients were included in the study (median age 60.9 [50.8-72.7] year, 70.2% male). Obese patients (BMI>30kgm^-2) were older, more frequently male and evidenced more frequently cardiovascular risk factors than normally (18.5<BMI<25kgm^-2) or overweight patients (25<BMI<30kgm^-2). Post-resuscitation shock and therapeutic hypothermia failure were more frequent in obese patients. Overall mortality at day-30 and one-year was 63.8 and 67.2%, respectively. After multivariate adjustment, BMI>30kgm^-2 was independently associated with day-30 mortality (Odds ratio [OR] in comparison with normally weight patients 2.45; 95% confidence interval [95%CI: 1.32-4.56; p<0.01]). Obesity was not associated with one-year mortality (Hazard ratio [HR] 0.99, 95%CI 0.21,4.67; p=0.99) while underweight was associated with one-year mortality in this subgroup of patients (Hazard ratio [HR] 3.94, 95%CI 1.11,14.01; p=0.03).

CONCLUSION

In the present study, obesity was independently associated with day-30 mortality in successfully resuscitated ICU TH OHCA patients. Further studies are needed to understand the mechanisms that underpin this finding.

Relation of Obesity to Survival After In-Hospital Cardiac Arrest

Previous studies have shown that obesity is paradoxically associated with improved outcomes in many cardiovascular (CV) disease states; however, whether obesity affects survival after in-hospital cardiac arrest (IHCA) has not been well examined. We queried the 2003 to 2011 Nationwide Inpatient Sample databases to identify all patients aged ≥18 years who underwent cardiopulmonary resuscitation for IHCA. Obese patients were identified using the co-morbidity variable for obesity, as defined in Nationwide Inpatient Sample databases. Survival to hospital discharge was compared between obese and nonobese patients using multivariate regression models. Of 836,289 patients with IHCA, 67,216 (8.0%) were obese. Obese patients were younger and more likely to be women compared with nonobese patients. Despite being younger, obese patients had significantly higher prevalence of most CV co-morbidities such as dyslipidemia, coronary artery disease, previous myocardial infarction, heart failure, diabetes mellitus, hypertension, peripheral vascular disease, and chronic renal failure (p <0.001 for all). Obese patients were more likely to have ventricular tachycardia or ventricular fibrillation as the initial cardiac arrest rhythm (22.3% vs 20.9%; p <0.001). After multivariate risk adjustment, obese patients had improved survival to hospital discharge compared with nonobese patients (31.4% vs 24.1%; unadjusted odds ratio 1.44, 95% CI 1.42 to 1.47, p <0.001; adjusted odds ratio 1.15, 95% CI 1.13 to 1.17, p <0.001). Similar results were seen in patients with CV or non-CV conditions as the primary diagnosis and in those with ventricular tachycardia/ventricular fibrillation or pulseless electrical activity/asystole as the cardiac arrest rhythm. In conclusion, this large retrospective analysis of a nationwide cohort of patients with IHCA demonstrated higher risk-adjusted odds of survival in obese patients, consistent with an "obesity paradox."

Sudden cardiac death and obesity

For individuals and the society as a whole, the increased risk of sudden cardiac death in obese patients is becoming a major challenge, especially since obesity prevalence has been increasing steadily around the globe. Traditional risk factors and obesity often coexist. Hypertension, diabetes, obstructive sleep apnea and metabolic syndrome are well-known risk factors for CV disease and are often present in the obese patient. Although the bulk of evidence is circumstantial, sudden cardiac death and obesity share common traditional CV risk factors. Structural, functional and metabolic factors modulate and influence the risk of sudden cardiac death in the obese population. Other risk factors such as left ventricular hypertrophy, increased number of premature ventricular complexes, altered QT interval and reduced heart rate variability are all documented in both obese and sudden cardiac death populations. The present review focuses on out-of-hospital sudden cardiac death and potential mechanisms leading to sudden cardiac death in this population.