Amol Mehta

Thermal Ablative Therapies and Immune Checkpoint Modulation: Can Locoregional Approaches Effect a Systemic Response?

Percutaneous image-guided ablation is an increasingly common treatment for a multitude of solid organ malignancies. While historically these techniques have been restricted to the management of small, unresectable tumors, there is an expanding appreciation for the systemic effects these locoregional interventions can cause. In this review, we summarize the mechanisms of action for the most common thermal ablation modalities and highlight the key advances in knowledge regarding the interactions between thermal ablation and the immune system.

Perioperative Strokes and Early Outcomes in Mitral Valve Surgery: A Nationwide Analysis

OBJECTIVE To demonstrate the role of perioperative stroke as an independent risk factor for in-hospital morbidity and mortality after mitral valve surgery and review the trends in the early outcomes of mitral valve surgery over the past decade. DESIGN Using data from the National Inpatient Sample database for analysis, all patients who underwent isolated mitral valve procedures were identified using International Classification of Diseases-Ninth Revision codes. Univariate and multivariate analyses of risk factors of in-hospital mortality and morbidity were performed. SETTING Multi-institutional. PARTICIPANTS The study comprised patients who underwent mitral valve procedures from 1999 to 2011. INTERVENTIONS Mitral valve repair or replacement. MEASUREMENTS AND MAIN RESULTS Data on 21,821 patients showed an in-hospital mortality of 5.5% and morbidity of 63.30% (p<0.05). Perioperative strokes were experienced by 3.89% of the cohort after isolated mitral valve surgery (p<0.05). Independent predictors of adverse outcomes were age, female sex, emergency surgery, arrhythmias, hypertension, renal failure, coagulopathy, neurologic disorders, weight loss, anemia, postoperative cardiac arrest, and myocardial infarction. Perioperative strokes were found to be the strongest risk factor for postoperative mortality (odds ratio 2.34, 95% confidence interval 1.83-2.98) and morbidity (odds ratio 4.53, 95% confidence interval 3.34-6.15). CONCLUSION Age, female sex, emergency surgery, arrhythmias, hypertension, renal failure, coagulopathy, neurologic disorders, weight loss, fluid and electrolyte imbalance, anemia, postoperative cardiac arrest, and myocardial infarction were found to be significant predictors of morbidity and mortality after mitral valve surgery, with perioperative strokes posing the strongest risk. The trends in the last 10 years indicated a decrease in mortality and an increase in morbidity. Preoperative risk stratification and intraoperative identification for impending strokes appear warranted.

Carotid artery stenosis as an independent risk factor for perioperative strokes following mitral valve surgical intervention

OBJECTIVE To examine the role of carotid stenosis (CS) and other independent risk factors of perioperative stroke following either mitral valve repair or replacement. METHODS Using data from the National Inpatient Sample (NIS) database for analysis, all patients who underwent either mitral valve repair or replacement were identified using ICD-9 codes. RESULTS A total of 79,583 patients who underwent either mitral valve replacement or repair were studied. 3.39% of the total cohort developed perioperative stroke. With a mean age of 62.78±0.23, there was a statistically significant amount of stroke cases in age ranges 65-74 and 75-84 (p<0.05). Risk stratification was done using Van Walraven (VWR) scoring and the cohort had a mean of 2.73±0.06. The following independent predictors were found to be significant: age, female gender, moderate and high VWR risk, both symptomatic and asymptomatic CS, atrial fibrillation, previous h/o smoking, and other cardiac valve procedures performed, and congestive heart failure (CHF). CONCLUSION CS is a significant risk factor for perioperative strokes following mitral valve surgery. Further prospective clinical studies are needed that look into risk stratification of patients for better patient selection and the question of whether carotid revascularization procedures will be beneficial in reducing stroke rates.

Delirium Following Transcatheter Aortic Valve Replacement: National Inpatient Sample Analysis

OBJECTIVE To investigate the risk factors for postoperative delirium and the impact of delirium on mortality and morbidity following transcatheter aortic valve implantation (TAVI). DESIGN Patients who underwent TAVI were identified using the International Classification of Diseases, 9th revision clinical modification codes from the National Inpatient Sample database. Statistical analysis of preoperative and perioperative risk factors was done to identify the independent risk factors for delirium after TAVI. SETTING Multi-institutional. PARTICIPANTS Patients who underwent TAVI from 2012 to 2013. INTERVENTIONS TAVI. MEASUREMENTS AND MAIN RESULTS Over the period of 2 years (2012-2013), 7,566 patients underwent TAVI. The incidence of delirium post-TAVI was 4.57% (345). Age >85 (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.01-1.05; p = 0.003), electrolyte abnormalities (OR 1.83; 95% CI 1.17-2.87; p = 0.008), prior neurologic illness (OR 1.67; 95% CI 1.10-3.15; p = 0.01), and weight loss in the hospital (OR 1.77; 95% CI 1.05-2.99; p = 0.03) were independent risk factors for postoperative delirium (POD). Unilateral or bilateral carotid stenosis did not predispose to the development of delirium. POD was an independent risk factor for procedural morbidity (OR 3.29; 95% CI 2.05-5.28; p < 0.001). POD did not increase the risk of in-house mortality after TAVI. CONCLUSION Age of >85, electrolyte disturbance, pre-existing neurologic disease and weight loss were found to be independent risk factors for delirium. POD was associated significantly with morbidity. Owing to a significant increase in the morbidity, a thorough screening protocol and effective strategies to predict, prevent, and treat postoperative delirium would reduce the cost associated with TAVI.

Carotid artery disease and periprocedural stroke risk after transcatheter aortic valve implantation

Objective/Background: To examine the role of carotid stenosis (CS) and other independent risk factors of perioperative stroke, following transcatheter aortic valve implantation (TAVI). Materials and Methods: Using data from the National Inpatient Sample database for analysis, patients who underwent TAVI were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Various preoperative and perioperative risk factors and their association with perioperative strokes were studied. Results: Data on 7566 patients who underwent a TAVI procedure from 2012 to 2013 were extracted. The average age of the patient population was 81.2 ± 0.32 years. The overall perioperative stroke rate in our patient cohort was 2.79%. Majority (94.6%) of the strokes were ischemic. Multivariate analysis showed the following independent risk factors for perioperative strokes after TAVI: female gender odds ratio (OR) = 2.25 (95% confidence interval [CI], 1.42–3.57), higher van Walraven score OR = 6.6 (95% CI = 3.71–11.73), bilateral CS OR = 4.46 (95% CI = 2.03–9.82), and TAVI with a cardiac procedure done under cardiopulmonary bypass OR = 2.84 (95% CI = 1.57–5.14). Conclusion: Bilateral carotid disease is a significant risk factor for perioperative strokes following TAVI. Preoperative screening with carotid Doppler to identify high-risk patients appears to be warranted. In addition, patients of female gender were found to have an increased risk for carotid disease.

Perioperative stroke as a predictor of mortality and morbidity in patients undergoing CABG

Perioperative stroke is a devastating neurological complication of Coronary Artery Bypass Grafting surgery (CABG). It results in significantly increased rates of mortality and morbidity and presents a significant financial burden to our healthcare system. It has not, however, been studied in a large population based sample. We aim to investigate the role of perioperative stroke as an independent risk factor for in-hospital mortality and morbidity following CABG, and to review trends in the early outcomes of CABG from the years 1999 to 2011. We hypothesize that perioperative stroke is an independent risk factor for in-hospital mortality and morbidity following CABG. We analyzed data from the 1999-2011 Nationwide Inpatient Sample, identifying patients who underwent CABG using ICD-9 and CCS codes. We excluded patients below the age of 18 and above the age of 100, and patients undergoing concomitant heart and/or vascular procedures. Analysis on our sample of 668,627 patients yielded an overall rate of perioperative stroke, mortality, and morbidity of 1.87%, 2.13%, and 49.07%, respectively. Along with age, risk category, gender, and other postoperative outcomes, perioperative stroke was found to be a strong predictor of mortality and morbidity, leading to more than a 5-fold risk of death and morbidity. From our study, we conclude that perioperative stroke remains a serious adverse outcome of CABG and is an independent predictor of mortality and morbidity. While rates of stroke and mortality are decreasing, morbidity continues to trend upwards. This study emphasizes the importance of prevention and early intervention in patients at risk for perioperative stroke.

Perioperative strokes after coronary artery bypass grafting with staged carotid endarterectomy: A nationwide perspective

STUDY OBJECTIVE To examine the risk of perioperative stroke on in-hospital morbidity and mortality in staged coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA) procedures. DESIGN The National Inpatient Sample (NIS) database was used to extract data on all patients who underwent staged CABG CEA procedures. They were identified using the ICD-9 (International Classification of Diseases, Ninth Revision-Clinical Modification) diagnosis and procedure codes. SETTING Multi-institutional. PATIENTS Patients who underwent staged CABG and CEA from 1999 to 2011. INTERVENTIONS Staged CABG and CEA procedures. MEASUREMENTS Various pre-operative, and perioperative risk factors and their association with in-hospital mortality and morbidity were studied. MAIN RESULTS The study cohort was grouped into 2761 patients who underwent staged CEA and CABG. The average age of the patient population was 69years. An in-hospital mortality of 4.96% (137) was observed. Staged procedures showed a morbidity rate of 69.21%. Patients with perioperative strokes had a mortality rate of 16.73% following staged procedures. Other notable risk factors for mortality and morbidity were post-operative myocardial infarction (MI) and congestive heart failure (CHF). CONCLUSION Analysis of 2761 patients over a period of 12years (1999-2011) indicate perioperative stroke to be a strong post-operative predicator of in-hospital mortality and morbidity for staged procedures. Other significant factors such as advancing age, female gender and comorbidities like CHF, left ventricular dysfunction (LVD) and post-operative MI should also be considered when determining patient risk. Further investigative studies on staged CABG and CEA procedures are needed for better patient selection and for implementing preventative strategies such as neuroprotective medication and neuromonitoring to minimize the risk of ischemic strokes.

Seizures After Intracerebral Hemorrhage: Incidence, Risk Factors, and Impact on Mortality and Morbidity

OBJECTIVE Spontaneous intracerebral hemorrhage (ICH) is one of the most frequent causes of epilepsy in the United States. However, reported risk factors for seizure after are inconsistent, and their impact on inpatient morbidity and mortality is unclear. We aimed to study the incidence, risk factors, and impact of seizures after ICH in a nationwide patient sample. METHODS We queried the Nationwide Inpatient Sample for patients admitted to the hospital with a primary diagnosis of ICH between the years 1999 and 2011. Patients were subsequently dichotomized into groups of those with a diagnosis consistent with seizure and those without. Multivariate logistic regression was used to assess risk factors for seizure in this patient sample, and the association between seizures and mortality and morbidity. Logistic regression was then used for trend analysis of incidence of seizure diagnoses over time. RESULTS We identified 220,075 patients admitted with a primary diagnosis of ICH. Of these, 11.87% had a diagnosis consistent with seizure. Factors associated with increased risk of seizure after ICH included higher categorical van Walraven score, encephalopathy, alcohol abuse, solid tumor, and prior stroke. Seizure was independently associated with decreased odds of morbidity (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.86-0.92) and mortality (OR, 0.75; 95% CI, 0.72-0.77) in multivariate models controlling for existing comorbidities. CONCLUSIONS Seizures after were associated with decreased mortality and morbidity despite attempts to correct for existing comorbidities. Continuous monitoring of these patients for seizures may not be necessary in all circumstances, despite their frequency.

Perioperative Stroke, In-Hospital Mortality, and Postoperative Morbidity Following Transcatheter Aortic Valve Implantation: A Nationwide Study

Background and Purpose Perioperative stroke is a significant complication of transcatheter aortic valve implantation (TAVI). This study aimed to quantify perioperative stroke as an independent risk factor for in-hospital mortality and postoperative morbidity in patients receiving TAVI. Methods A retrospective cohort study was conducted using the National Inpatient Sample. Patients undergoing TAVI during 2012 and 2013 were identified using diagnostic codes of International Classification of Diseases, ninth revision. Univariate and multivariate analyses were performed using patient demographics and comorbidities to identify predictors of mortality and morbidity, defined by a length of stay of >14 days and/or discharge to a place other than home. Results Data were obtained from 7,556 patients undergoing TAVI during 2012 and 2013. The incidence rates of mortality and morbidity were 4.57 and 71.12%, respectively. Perioperative stroke was an independent risk factor for mortality [odds ratio (OR)=3.182, 95% confidence interval (CI)=1.530–6.618, p=0.002], as were infection (OR=17.899, 95% CI=9.876–32.440, p<0.001) and pericardial tamponade (OR=7.272, 95% CI=2.874–18.402, p<0.001). Stroke also predicted morbidity (OR=5.223, 95% CI=2.005–13.608, p=0.001), which was also associated with age, being female, being Asian, moderate and high Van Walraven scores (VWR), and infection. Conclusions In conclusion, perioperative stroke was found to be independently associated with in-hospital mortality and postoperative morbidity, as are age and high VWR. Our findings support the use of further preoperative, intraoperative, and postoperative management strategies during TAVI.

Carotid Artery Disease as a Predictor of In-Hospital Postoperative Stroke After Coronary Artery Bypass Grafting From 1999 to 2011

BACKGROUND In this study, the risk factors for stroke after coronary artery bypass grafting (CABG) were examined. In particular, the role of asymptomatic carotid artery stenosis (both unilateral and bilateral) as a predictor of in-hospital postoperative stroke was investigated. Finally, the trends surrounding in-hospital postoperative stroke from 1999 to 2011 also were examined. The purpose of the study was to appropriately identify patients at high risk for stroke after CABG and spark discussion about the perioperative management of such patients. MATERIALS AND METHODS Data from the Nationwide Inpatient Sample from 1999 to 2011 were analyzed retrospectively. The study cohort was identified using the International Classification of Diseases, Ninth Revision, Clinical Modification and Projection Clinical Classification Software codes. Exploratory statistics, univariate analyses, and multivariable regression were used for this study. RESULTS The analysis demonstrated that both asymptomatic unilateral and bilateral carotid stenoses were independent risk factors for in-hospital postoperative stroke. In addition, increasing age, female sex, increasing van Walraven score, paralysis, neurologic disorders, history of infective endocarditis, asymptomatic basilar stenosis, and cerebral occlusion all were demonstrated to be statistically significant predictors of stroke. Patients with carotid stenosis and a van Walraven score >14 were found to be particularly vulnerable to in-hospital postoperative stroke. Lastly, predictors of carotid stenosis were examined, and increasing age, female sex, and increasing van Walraven score all were found to be significant predictors of asymptomatic carotid stenosis. CONCLUSIONS This study examined risk factors for stroke after CABG in a large, longitudinal, and population-based database. The study found that both unilateral and bilateral asymptomatic carotid stenoses are indeed risk factors for in-hospital postoperative stroke. In addition, a number of other predictors were identified. These results can be used to identify patients at high risk for perioperative stroke and hopefully decrease the rate of a devastating complication of CABG.