Catheter ablation of postinfarction ventricular tachycardia: ten-year trends in utilization, in-hospital complications, and in-hospital mortality in the United States

BACKGROUND

There is a paucity of data regarding the complications and in-hospital mortality after catheter ablation for ventricular tachycardia (VT) in patients with ischemic heart disease.

OBJECTIVE

The purpose of this study was to determine the temporal trends in utilization, in-hospital mortality, and complications of catheter ablation of postinfarction VT in the United States.

METHODS

We used the 2002-2011 Nationwide Inpatient Sample (NIS) database to identify all patients ≥18 years of age with a primary diagnosis of VT (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code 427.1) and who also had a secondary diagnosis of prior history of myocardial infarction (ICD-9-CM 412). Patients with supraventricular arrhythmias were excluded. Patients who underwent catheter ablation were identified using ICD-9-CM procedure code 37.34. Temporal trends in catheter ablation, in-hospital complications, and in-hospital mortality were analyzed.

RESULTS

Of 81,539 patients with postinfarct VT, 4653 (5.7%) underwent catheter ablation. Utilization of catheter ablation increased significantly from 2.8% in 2002 to 10.8% in 2011 (Ptrend < .001). The overall rate of any in-hospital complication was 11.2% (523/4653), with vascular complications in 6.9%, cardiac in 4.3%, and neurologic in 0.5%. In-hospital mortality was 1.6% (75/4653). From 2002 to 2011, there was no significant change in the overall complication rates (8.4% to 10.2%, Ptrend = .101; adjusted odds ratio [per year] 1.02, 95% confidence interval 0.98-1.06) or in-hospital mortality (1.3% to 1.8%, Ptrend = .266; adjusted odds ratio [per year] 1.03, 95% confidence interval 0.92-1.15).

CONCLUSION

The utilization rate of catheter ablation as therapy for postinfarct VT has steadily increased over the past decade. However, procedural complication rates and in-hospital mortality have not changed significantly during this period.

Cardiac involvement in hemochromatosis

Cardiac hemochromatosis or primary iron-overload cardiomyopathy is an important and potentially preventable cause of heart failure. This is initially characterized by diastolic dysfunction and arrhythmias and in later stages by dilated cardiomyopathy. Diagnosis of iron overload is established by elevated transferrin saturation (>55%) and elevated serum ferritin (>300 ng/mL). Genetic testing for mutations in the HFE (high iron) gene and other proteins, such as hemojuvelin, transferrin receptor, and ferroportin, should be performed if secondary causes of iron overload are ruled out. Patients should undergo comprehensive 2D and Doppler echocardiography to evaluate their systolic and diastolic function. Newer modalities like strain imaging and speckle-tracking echocardiography hold promise for earlier detection of cardiac involvement. Cardiac magnetic resonance imaging with measurement of T2* relaxation times can help quantify myocardial iron overload. In addition to its value in diagnosis of cardiac iron overload, response to iron reduction therapy can be assessed by serial imaging. Therapeutic phlebotomy and iron chelation are the cornerstones of therapy. The average survival is less than a year in untreated patients with severe cardiac impairment. However, if treated early and aggressively, the survival rate approaches that of the regular heart failure population.

Smoker's Paradox in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Prior studies have found that smokers undergoing thrombolytic therapy for ST-segment elevation myocardial infarction have lower in-hospital mortality than nonsmokers, a phenomenon called the "smoker's paradox." Evidence, however, has been conflicting regarding whether this paradoxical association persists in the era of primary percutaneous coronary intervention.

METHODS AND RESULTS

We used the 2003-2012 National Inpatient Sample databases to identify all patients aged ≥18 years who underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. Multivariable logistic regression was used to compare in-hospital mortality between smokers (current and former) and nonsmokers. Of the 985 174 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, 438 954 (44.6%) were smokers. Smokers were younger, were more often men, and were less likely to have traditional vascular risk factors than nonsmokers. Smokers had lower observed in-hospital mortality compared with nonsmokers (2.0% versus 5.9%; unadjusted odds ratio 0.32, 95% CI 0.31-0.33, P<0.001). Although the association between smoking and lower in-hospital mortality was partly attenuated after baseline risk adjustment, a significant residual association remained (adjusted odds ratio 0.60, 95% CI 0.58-0.62, P<0.001). This association largely persisted in age-stratified analyses. Smoking status was also associated with shorter average length of stay (3.5 versus 4.5 days, P<0.001) and lower incidence of postprocedure hemorrhage (4.2% versus 6.1%; adjusted odds ratio 0.81, 95% CI 0.80-0.83, P<0.001) and in-hospital cardiac arrest (1.3% versus 2.1%; adjusted OR 0.78, 95% CI 0.76-0.81, P<0.001).

CONCLUSIONS

In this nationwide cohort of patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, we observed significantly lower risk-adjusted in-hospital mortality in smokers, suggesting that the smoker's paradox also applies to ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention.

Association of chronic renal insufficiency with in-hospital outcomes after percutaneous coronary intervention

BACKGROUND

The association of chronic renal insufficiency with outcomes after percutaneous coronary intervention (PCI) in the current era of drug-eluting stents and modern antithrombotic therapy has not been well characterized.

METHODS AND RESULTS

We queried the 2007-2011 Nationwide Inpatient Sample databases to identify all patients aged ≥18 years who underwent PCI. Multivariable logistic regression was used to compare in-hospital outcomes among patients with chronic kidney disease (CKD), patients with end-stage renal disease (ESRD), and those without CKD or ESRD. Of 3 187 404 patients who underwent PCI, 89% had no CKD/ESRD; 8.6% had CKD; and 2.4% had ESRD. Compared to patients with no CKD/ESRD, patients with CKD and patients with ESRD had higher in-hospital mortality (1.4% versus 2.7% versus 4.4%, respectively; adjusted odds ratio for CKD 1.15, 95% CI 1.12 to 1.19, P<0.001; adjusted odds ratio for ESRD 2.29, 95% CI 2.19 to 2.40, P<0.001), higher incidence of postprocedure hemorrhage (3.5% versus 5.4% versus 6.0%, respectively; adjusted odds ratio for CKD 1.21, 95% CI 1.18 to 1.23, P<0.001; adjusted odds ratio for ESRD 1.27, 95% CI 1.23 to 1.32, P<0.001), longer average length of stay (2.9 days versus 5.0 days versus 6.4 days, respectively; P<0.001), and higher average total hospital charges ($60 526 versus $77 324 versus $97 102, respectively; P<0.001). Similar results were seen in subgroups of patients undergoing PCI for acute coronary syndrome or stable ischemic heart disease.

CONCLUSIONS

In patients undergoing PCI, chronic renal insufficiency is associated with higher in-hospital mortality, higher postprocedure hemorrhage, longer average length of stay, and higher average hospital charges.

Cardiogenic shock during heart failure hospitalizations: Age-, sex-, and race-stratified trends in incidence and outcomes

The objectives were to study the overall and age-, sex-, and race-stratified incidence of cardiogenic shock (CS) during heart failure hospitalizations (HFHs) not complicated by acute coronary syndromes (ACS), utilization of short-term mechanical circulatory support (MCS) and in-hospital mortality with non-ACS-related CS, and respective temporal trends. Data are lacking regarding the epidemiology of non-ACS-related CS during HFHs.

METHODS

Retrospective observational analysis of the National Inpatient Sample 2005-2014 to identify all HFHs in adult patients without concomitant ACS.

RESULTS

Of 8,333,752 HFHs, incidence rate of non-ACS-related CS was 8.7 per thousand HFHs (N = 72,668), a 4-fold increase from 4.1 to 15.6 per thousand HFHs between 2005 and 2014 (Ptrend < .001). Among those with non-ACS-related CS, utilization rates of intra-aortic balloon pump, extracorporeal membrane oxygenation, and temporary ventricular assist devices were 12.8%, 1.4%, and 2.5%, respectively. Respective 2005 to 2014 trends were 14.2% to 10.7%, 0.6% to 1.8%, and 0.8% to 2.7% (Ptrend for all, <.001). In-hospital mortality rate was 27.1%, with a substantial decrease from 42.4% in 2005 to 23.3% in 2014 (Ptrend < .001). These temporal trends were largely consistent across age, sex, and race subgroups.

CONCLUSION

During HFHs in the United States, non-ACS-related CS occurred infrequently but was associated with substantial mortality. Non-ACS-related CS incidence and certain MCS utilization rates increased, and in-hospital mortality rate decreased between 2005 and 2014. These trends were generally homogenous across the age, sex, and race groups. The observed trends in incidence and mortality may be a reflection of increased identification of CS during HFHs, although further study is needed to assess whether temporal changes in care may have influenced outcomes.

Trends in management and outcomes of ST-elevation myocardial infarction in patients with end-stage renal disease in the United States

Acute myocardial infarction in patients with end-stage renal disease (ESRD) is associated with increased risk of morbidity and mortality. Limited data are available on the contemporary trends in management and outcomes of ST-elevation myocardial infarction (STEMI) in patients with ESRD. We analyzed the 2003 to 2011 Nationwide Inpatient Sample databases to examine the temporal trends in STEMI, use of mechanical revascularization for STEMI, and in-hospital outcomes in patients with ESRD aged ≥18 years in the United States. From 2003 to 2011, whereas the number of patients with ESRD admitted with the primary diagnosis of acute myocardial infarction increased from 13,322 to 20,552, there was a decrease in the number of STEMI hospitalizations from 3,169 to 2,558 (ptrend <0.001). The overall incidence rate of cardiogenic shock in patients with ESRD and STEMI increased from 6.6% to 18.3% (ptrend <0.001). The use of percutaneous coronary intervention for STEMI increased from 18.6% to 37.8% (ptrend <0.001), whereas there was no significant change in the use of coronary artery bypass grafting (ptrend = 0.32). During the study period, in-hospital mortality increased from 22.3% to 25.3% (adjusted odds ratio [per year] 1.09; 95% confidence interval 1.08 to 1.11; ptrend <0.001). The average hospital charges increased from $60,410 to $97,794 (ptrend <0.001), whereas the average length of stay decreased from 8.2 to 6.5 days (ptrend <0.001). In conclusion, although there have been favorable trends in the utilization of percutaneous coronary intervention and length of stay in patients with ESRD and STEMI, the incidence of cardiogenic shock has increased threefold, with an increase in risk-adjusted in-hospital mortality, likely because of the presence of greater co-morbidities.

Outcomes of acute myocardial infarction in patients with hypertrophic cardiomyopathy

BACKGROUND

Acute myocardial infarction is a recognized complication in patients with hypertrophic cardiomyopathy. However, limited data are available on outcomes of patients with hypertrophic cardiomyopathy and acute myocardial infarction.

METHODS

We analyzed the 2003-2011 Nationwide Inpatient Sample databases to identify all patients aged ≥18 years with a principal diagnosis of acute myocardial infarction. Patients with a concomitant diagnosis of hypertrophic cardiomyopathy were then identified and analyzed as a separate cohort. Multivariate logistic regression was used to compare outcomes in patients with acute myocardial infarction with and without hypertrophic cardiomyopathy.

RESULTS

Of 5,901,827 patients with acute myocardial infarction, 5688 (0.1%) had a diagnosis of hypertrophic cardiomyopathy. Patients with hypertrophic cardiomyopathy were older, more likely to be female, and less likely to have traditional cardiovascular risk factors. Compared with patients without hypertrophic cardiomyopathy, patients with hypertrophic cardiomyopathy were less likely to present with ST-elevation myocardial infarction and more likely to present with non-ST-elevation myocardial infarction. Patients with hypertrophic cardiomyopathy with ST-elevation myocardial infarction or non-ST-elevation myocardial infarction were less likely to receive revascularization. In the overall population with acute myocardial infarction, there was no difference in risk-adjusted in-hospital mortality between patients with and without hypertrophic cardiomyopathy (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.84-1.11; P = .59). In the population with ST-elevation myocardial infarction, patients with hypertrophic cardiomyopathy had lower risk-adjusted in-hospital mortality than those without hypertrophic cardiomyopathy (OR, 0.75; 95% CI, 0.63-0.91; P = .003), whereas in the population with non-ST-elevation myocardial infarction, there was no difference in risk-adjusted in-hospital mortality between patients with and without hypertrophic cardiomyopathy (OR, 0.97; 95% CI, 0.84-1.11; P = .63).

CONCLUSIONS

Patients with hypertrophic cardiomyopathy represent a small proportion of patients with acute myocardial infarction and are less likely to receive revascularization. Compared with patients without hypertrophic cardiomyopathy, patients with hypertrophic cardiomyopathy with ST-elevation myocardial infarction have lower risk-adjusted in-hospital mortality.

Risk Factors and Outcomes During a First Acute Myocardial Infarction in Breast Cancer Survivors Compared with Females Without Breast Cancer

PURPOSE

The purpose of this research was to study the differences in epidemiology and outcomes of a first myocardial infarction in breast cancer survivors compared with the general female population in the United States.

METHODS

We retrospectively analyzed the US National Inpatient Sample years 2005-2015 to identify adult women with a first myocardial infarction. In this cohort, breast cancer survivors were identified. Outcomes evaluated were the differences in baseline demographics, comorbidities, and adjusted in-hospital mortality in women with and without breast cancer.

RESULTS

Among 1,644,032 first myocardial infarction cases in adult women, there were 56,842 (3.5%) breast cancer survivors. Compared with women without breast cancer, breast cancer survivors were 6 years older (mean age 77 vs 71 years, P < .001), had significantly higher prevalence of dyslipidemia and hypertension, and lower prevalence of obesity, diabetes mellitus, and smoking. Breast cancer survivors were more likely to have a non-ST segment elevation acute myocardial infarction and less likely to receive mechanical revascularization. In-hospital mortality was lower in breast cancer survivors (7.1%) compared with those without (7.9%, P < .001), findings that persisted after risk adjustment (odds ratio 0.89; 95% CI, 0.82-0.94).

CONCLUSIONS

Breast cancer survivors had a first acute myocardial infarction at an older age and had small but favorable differences in cardiovascular disease risk factors and outcomes compared with women without breast cancer. The favorable impact of health education, preventative medical care, greater motivation for a healthier lifestyle, and participation in cancer survivorship programs on these seemingly paradoxical findings in breast cancer survivors should be further explored.

Cardiac Resynchronization Therapy for Heart Failure

Cardiac resynchronization therapy (CRT) has emerged as a valued nonpharmacologic therapy in patients with heart failure, reduced ejection fraction (EF), and ventricular dyssynchrony manifest as left bundle branch block. The mechanisms of benefit include remodeling of the left ventricle leading to decreased dimensions and increased EF, as well as a decrease in the severity of mitral regurgitation. This article reviews the rationale, effects, and indications for CRT, and discusses the patient characteristics that predict response and considerations for nonresponders.

Association of corrected QT interval with long-term mortality in patients with syncope

INTRODUCTION

The electrocardiographic parameters QRS duration, QRS-T angle and QTc can predict mortality in patients with cardiovascular disease. The prgnostic value of these parameters in hospitalized patients with syncope needs investigation.

MATERIAL AND METHODS

We retrospectively studied 590 consecutive patients hospitalized with syncope. After excluding patients with baseline abnormal rhythm, QT- prolonging medications, and missing data, 459 patients were analyzed. Baseline demographic characteristics, co-morbidities, medication use, San Francisco Syncope Rule (SFSR) and Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) score and data on mortality were collected. The categorical variables and continuous variables of the 2 groups of patients with prolonged QTc and normal QTc interval were analyzed by Fischer's exact test and Mann-Whitney Test. A stepwise Cox regression model was used for time to death analysis.

RESULTS

Of 459 patients, prolonged QTc interval was observed in 122 (27%). Mean follow-up was 41 months. Patients with prolonged QTc interval had higher prevalence of cardiovascular disease, OESIL score, high risk SFSR, hypertension, dyslipidemia, coronary artery disease, congestive heart failure, and increased mortality. Stepwise Cox regression analysis showed that significant independent prognostic factors for time to death were prolonged QTc interval (p = 0.005), age (p = 0.001), diabetes mellitus (p = 0.001) and history of malignancy (p = 0.006). QRS duration and QRS-T angle were not independent predictors of mortality.

CONCLUSIONS

A prolonged QTc interval is an independent predictor of long-term mortality in hospitalized patients with syncope.

Update on pharmacologic therapy for pulmonary embolism

Warfarin, unfractionated heparin (UFH), and low-molecular-weight heparins are anticoagulants that have been used for treatment of pulmonary embolism. Currently approved drugs for treatment of venous thromboembolism include UFH, enoxaparin, dalteparin, fondaparinux, warfarin, and rivaroxaban. The advent of newer oral anticoagulants such as rivaroxaban, dabigatran, and apixaban has provided us with alternative therapeutic options for long-term anticoagulation. This article will give an overview of the various anticoagulant drugs, use in various clinical scenarios, data supporting their clinical use, and recommendations regarding duration of anticoagulant therapy.

Coronary artery disease in patients with human immunodeficiency virus infection

The life expectancy of people infected with human immunodeficiency virus (HIV) is rising due to better access to combination anti-retroviral therapy (ART). Although ART has reduced acquired immune deficiency syndrome (AIDS) related mortality and morbidity, there has been an increase in non-AIDS defining illnesses such as diabetes mellitus, hypercholesterolemia and coronary artery disease (CAD). HIV is a disease marked by inflammation which has been associated with specific biological vascular processes increasing the risk of premature atherosclerosis. The combination of pre-existing risk factors, atherosclerosis, ART, opportunistic infections and coagulopathy contributes to rising CAD incidence. The prevalence of CAD has emerged as a major contributor of morbidity in these patients due to longer life expectancy. However, ART has been associated with lipodystrophy, dyslipidemia, insulin resistance, diabetes mellitus and CAD. These adverse effects, along with drug-drug interactions when ART is combined with cardiovascular drugs, result in significant challenges in the care of this group of patients. Exercise tolerance testing, echocardiography, myocardial perfusion imaging, coronary computed tomography angiography and magnetic resonance imaging help in the diagnosis of CAD and heart failure and help predict cardiovascular outcomes in a manner similar to non-infected individuals. This review will highlight the pathogenesis and factors that link HIV to CAD, presentation and treatment of HIV-patients presenting with CAD and review briefly the cardiac imaging modalities used to identify this entity and help prognosticate future outcomes.

Newer hormonal pharmacotherapies for heart failure

INTRODUCTION

Heart failure (HF) is characterized by maladaptive neurohormonal activation of the cardiovascular and renal systems resulting in circulatory inadequacy and frequent acute exacerbations. The increasing burden of HF prompted investigation of underlying pathophysiological mechanisms and the design of pharmacotherapeutics that would target these pathways.

AREAS COVERED

A MEDLINE search for relevant original investigations and review articles of newer hormonal drugs for HF since the year 2005 till October 2017 provided us with necessary literature. Major trials and relevant clinical investigations were discussed.

EXPERT COMMENTARY

A multitude of hormonal pathways central to HF were identified, including the natriuretic peptide system and neurohormones such as relaxin, arginine vasopressin, and endothelin. However, drugs targeting these novel pathways (aliskiren, tolvaptan, ularitide, serelaxin, bosentan, macitentan) failed to show mortality benefit. This emphasizes a tremendous unmet need in the pharmacotherapy for HF, especially for the subtypes of acute HF and HF with preserved ejection fraction. Sacubitril/valsartan demonstrated substantial mortality benefit in chronic systolic HF population and is endorsed by international HF guidelines. If proven to be efficacious in larger outcome trials, finerenone can be a valuable addition baseline HF therapy. More basic, translational, and phenotype specific clinical research is warranted to improve HF pharmacotherapy.

Impact of Acute and Chronic Kidney Disease on Heart Failure Hospitalizations After Acute Myocardial Infarction

Very few studies evaluated the impact of acute kidney injury (AKI) and chronic kidney disease (CKD) on heart failure (HF) hospitalization risk following an acute myocardial infarction (AMI). For this retrospective cohort analysis, we identified adult AMI survivors from January to June 2014 from the United States Nationwide Readmissions Database. Outcomes were a 6-month HF, fatal HF, composite of HF during the AMI or a 6-month HF, and a composite of 6-month HF or death during a non-HF-related admission. We analyzed differences in outcomes across categories of patients without renal injury, AKI without CKD, stable CKD, AKI on CKD, and end-stage renal disease (ESRD). Of 237,549 AMI survivors, AKI was present in 13.8%, CKD in 16.5%, ESRD in 3.4%, and AKI on CKD in 7.7%. Patients with renal failure had lower coronary revascularization rates and higher in-hospital HF. A 6-month HF hospitalization occurred in 12,934 patients (5.4%). Compared with patients without renal failure (3.3%), 6-month HF admission rate was higher in patients with AKI on CKD (14.6%; odds ratio [OR] 1.99; 95% confidence interval [CI] 1.81 to 2.19), ESRD (11.2%; OR 1.57; 95% CI 1.36 to 1.81), stable CKD (10.7%; OR 1.72; 95% CI 1.56 to 1.88), and AKI (8.6%; OR 1.52; 95% CI 1.36 to 1.70). Results were generally homogenous in prespecified subgroups and for the other outcomes. In conclusion, 1 in 4 AMI survivors had either acute or chronic renal failure. The presence of any form of renal failure was associated with a substantially increased risk of 6-month HF hospitalizations and associated mortality with the highest risk associated with AKI on CKD.