Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009).

BACKGROUND: The relationship between operator or institutional volume and outcomes among patients undergoing percutaneous coronary interventions (PCI) is unclear. METHODS AND RESULTS: Cross-sectional study based on the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample between 2005 to 2009. Subjects were identified by International Classification of Diseases, 9(th) Revision, Clinical Modification procedure code, 36.06 and 36.07. Annual operator and institutional volumes were calculated using unique identification numbers and then divided into quartiles. Three-level hierarchical multivariate mixed models were created. The primary outcome was in-hospital mortality; secondary outcome was a composite of in-hospital mortality and peri-procedural complications. A total of 457,498 PCIs were identified representing a total of 2,243,209 PCIs performed in the United States during the study period. In-hospital, all-cause mortality was 1.08%, and the overall complication rate was 7.10%. The primary and secondary outcomes of procedures performed by operators in 4(th) [annual procedural volume; primary and secondary outcomes] [>100; 0.59% and 5.51%], 3(rd) [45-100; 0.87% and 6.40%], and 2(nd) quartile [16-44; 1.15% and 7.75%] were significantly less (P<0.001) when compared with those by operators in the 1(st) quartile [≤15; 1.68% and 10.91%]. Spline analysis also showed significant operator and institutional volume outcome relationship. Similarly operators in the higher quartiles witnessed a significant reduction in length of hospital stay and cost of hospitalization (P<0.001). CONCLUSIONS: Overall in-hospital mortality after PCI was low. An increase in operator and institutional volume of PCI was found to be associated with a decrease in adverse outcomes, length of hospital stay, and cost of hospitalization.

In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.

BACKGROUND: Atrial fibrillation ablation has made tremendous progress with respect to innovation, efficacy, and safety. However, limited data exist regarding the burden and trends in adverse outcomes arising from this procedure. The aim of our study was to examine the frequency of adverse events attributable to atrial fibrillation (AF) ablation and the influence of operator and hospital volume on outcomes. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample, we identified AF patients treated with catheter ablation. We investigated common complications including cardiac perforation and tamponade, pneumothorax, stroke, transient ischemic attack, vascular access complications (hemorrhage/hematoma, vascular complications requiring surgical repair, and accidental arterial puncture), and in-hospital death described with AF ablation, and we defined these complications by using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. An estimated 93,801 AF ablations were performed from 2000 to 2010. The overall frequency of complications was 6.29% with combined cardiac complications (2.54%) being the most frequent. Cardiac complications were followed by vascular complications (1.53%), respiratory complications (1.3%), and neurological complications (1.02%). The in-hospital mortality was 0.46%. Annual operator (<25 procedures) and hospital volume (<50 procedures) were significantly associated with adverse outcomes. There was a small (nonsignificant) rise in overall complication rates. CONCLUSIONS: The overall complication rate was 6.29% in patients undergoing AF ablation. There was a significant association between operator and hospital volume and adverse outcomes. This suggests a need for future research into identifying the safety measures in AF ablations and instituting appropriate interventions to improve overall AF ablation outcomes.

Spontaneous coronary artery dissection in a patient with autosomal dominant polycystic kidney disease: a case report.

BACKGROUND: Spontaneous coronary artery dissection is an uncommon syndrome. Its prevalence among patients with polycystic kidney disease is very rare, with no previously reported involvement of the right posterior descending coronary artery. CASE PRESENTATION: We describe the case of a middle-aged Caucasian woman with polycystic kidney disease who presented with a non-ST elevation myocardial infarction. Cardiac catheterization revealed a dissection of her right posterior descending coronary artery. She was treated with dual antiplatelet therapy and had a favorable outcome. CONCLUSION: We report a rare and interesting case of spontaneous coronary artery dissection of the right posterior descending coronary artery in a patient with polycystic kidney disease. It is important to consider spontaneous coronary artery dissection in the differential diagnosis of patients with polycystic kidney disease who present with an acute coronary syndrome.

Utilization and adverse outcomes of percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation in the United States: influence of hospital volume.

BACKGROUND: Safety data on percutaneous left atrial appendage closure arises from centers with considerable expertise in the procedure or from clinical trial, which might not be reproducible in clinical practice. We sought to estimate the frequency and predictors of adverse outcomes and costs of percutaneous left atrial appendage closure procedure in the US. METHODS AND RESULTS: The data were obtained from the Nationwide Inpatient Sample from the years 2006 to 2010. The Nationwide Inpatient Sample is the largest all-payer inpatient data set in the US. Complications were calculated using patient safety indicators and International Classification of Diseases-Ninth Revision, Clinical Modification codes. Annual hospital volume was calculated using unique hospital identifiers. Weights provided by the Nationwide Inpatient Sample were used to generate national estimates. A total of 268 (weighted=1288) procedures were analyzed. The overall composite rate of mortality or any adverse event was 24.3% (65), with 3.4% patients required open cardiac surgery after procedure. Average length of stay was 4.61±1.05 days and cost of care was 26,024±34,651. Annual hospital procedural volume was significantly associated with reduced complications and mortality (every unit increase: odds ratio, 0.89; 95% confidence interval, 0.85-0.94; P<0.001), decrease in length of stay (every unit increase: hazard ratio, 0.95; 95% confidence interval, 0.92-0.98; P<0.001) and cost of care (every unit increase: hazard ratio, 0.96; 95% confidence interval, 0.93-0.98; P<0.001). CONCLUSIONS: Our study demonstrates that the frequency of inhospital adverse outcomes associated with percutaneous left atrial appendage closure is higher in the real-world population than in clinical trials. We also demonstrate that higher annual hospital volume is associated with safer procedures, with lower length of stay and cost.

Results of ventricular septal myectomy and hypertrophic cardiomyopathy (from Nationwide Inpatient Sample [1998-2010]).

Ventricular septal myomectomy (VSM) is the primary modality for left ventricular outflow tract gradient reduction in patients with obstructive hypertrophic cardiomyopathy with refractory symptoms. Comprehensive postprocedural data for VSM from a large multicenter registry are sparse. The primary objective of this study was to evaluate postprocedural mortality, complications, length of stay (LOS), and cost of hospitalization after VSM and to further appraise the multivariate predictors of these outcomes. The Healthcare Cost and Utilization Project's Nationwide Inpatient Sample was queried from 1998 through 2010 using International Classification of Diseases, Ninth Revision, procedure codes 37.33 for VSM and 425.1 for hypertrophic cardiomyopathy. The severity of co-morbidities was defined using the Charlson co-morbidity index. Hierarchical mixed-effects models were generated to identify independent multivariate predictors of in-hospital mortality, procedural complications, LOS, and cost of hospitalization. The overall mortality was 5.9%. Almost 9% (8.7%) of patients had postprocedural complete heart block requiring pacemakers. Increasing Charlson co-morbidity index was associated with a higher rate of complications and mortality (odds ratio 2.41, 95% confidence interval 1.17 to 4.98, p = 0.02). The mean cost of hospitalization was $41,715 ± $1,611, while the average LOS was 8.89 ± 0.35 days. Occurrence of any postoperative complication was associated with increased cost of hospitalization (+$33,870, p <0.001) and LOS (+6.08 days, p <0.001). In conclusion, the postoperative mortality rate for VSM was 5.9%; cardiac complications were most common, specifically complete heart block. Age and increasing severity of co-morbidities were predictive of poorer outcomes, while a higher burden of postoperative complications was associated with a higher cost of hospitalization and LOS.

Optimal blood pressure in patients with atrial fibrillation (from the AFFIRM Trial).

Many medications used to treat atrial fibrillation (AF) also reduce blood pressure (BP). The relation between BP and mortality is unclear in patients with AF. We performed a post hoc analysis of 3,947 participants from the Atrial Fibrillation Follow-Up Investigation of Rhythm Management trial. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline and follow-up were categorized by 10-mm Hg increments. The end points were all-cause mortality (ACM) and secondary outcome (combination of ACM, ventricular tachycardia and/or fibrillation, pulseless electrical activity, significant bradycardia, stroke, major bleeding, myocardial infarction, and pulmonary embolism). SBP and DBP followed a "U-shaped" curve with respect to primary and secondary outcomes after multivariate analysis. A nonlinear Cox proportional hazards model showed that the incidence of ACM was lowest at 140/78 mm Hg. Subgroup analyses revealed similar U-shaped curves. There was an increased ACM observed with BP <110/60 mm Hg (hazard ratio 2.4, p <0.01, respectively, for SBP and DBP). In conclusion, in patients with AF, U-shaped relation existed between BP and ACM. These data suggest that the optimal BP target in patients with AF may be greater than the general population and that pharmacologic therapy to treat AF may be associated with ACM or adverse events if BP is reduced to <110/60 mm Hg.

Impact of symptoms, gender, co-morbidities, and operator volume on outcome of carotid artery stenting (from the Nationwide Inpatient Sample [2006 to 2010]).

The increase in the number of carotid artery stenting (CAS) procedures over the last decade has necessitated critical appraisal of procedural outcomes and patterns of utilization including cost analysis. The main objectives of our study were to evaluate the postprocedural mortality and complications after CAS and the patterns of resource utilization in terms of length of stay (LOS) and cost of hospitalization. We queried the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample from 2006 to 2010 using the International Classification of Diseases, Ninth Revision, procedure code of 00.63 for CAS. Hierarchical mixed-effects models were generated to identify the independent multivariate predictors of in-hospital mortality, procedural complications, LOS, and cost of hospitalization. A total of 13,564 CAS procedures (weighted n = 67,344) were analyzed. The overall postprocedural mortality was low at 0.5%, whereas the complication rate was 8%, both of which remained relatively steady over the time frame of the study. Greater postoperative mortality and complications were noted in symptomatic patients, women, and those with greater burden of baseline co-morbidities. A greater operator volume was associated with a lower rate of postoperative mortality and complications, as well as shorter LOS and lesser hospitalization costs. In conclusion, the postprocedural mortality after CAS has remained low over the recent years. Operator volume is an important predictor of postprocedural outcomes and resource utilization.

Impact on in-hospital outcomes with drug-eluting stents versus bare-metal stents (from 665,804 procedures).

Contemporary large-scale data, regarding in-hospital outcomes depending on the types of stent used for percutaneous coronary intervention (PCI) is lacking. We queried the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample from 2006 to 2011 using the International Classification of Diseases, Ninth Revision, Clinical Modification procedure code 36.06 (bare-metal coronary artery stent, BMS) or 36.07 (drug-eluting coronary artery stent, DES) for PCI. All analyses were performed using the designated weighting specified to the Nationwide Inpatient Sample database to minimize bias. Primary outcome was in-hospital mortality. Wald's chi-square test was used for categorical variables. We built a hierarchical 2 level model adjusted for multiple confounding factors, with hospital identification incorporated as random effects in the model and propensity match analyses were used to adjust confounding variables. A total of 665,804 procedures were analyzed, which were representative of 3,277,884 procedures in the United States. Use of bare-metal stents (BMS) was associated with greater occurrence of in-hospital mortality compared with that of drug-eluting stents (DES; 1.4% vs 0.5%, p <0.001). The association stayed significant after adjustment of various possible confounding factors (odds ratio for DES versus BMS 0.59 [0.54 to 0.64, p <0.001]) and also in propensity matched cohorts (1.2% vs 0.7%, p <0.001). The results continued to be similar in the following high-risk subgroups: diabetes (0.57 [0.50 to 0.64, <0.001]), acute myocardial infarction and/or shock (0.53 [0.49 to 0.57, <0.001]), age >80 (0.66 [0.58 to 0.74, <0.001]), and multivessel PCI (0.55 [0.46 to 0.66, <0.001]). In conclusion, DES use was associated with lesser in-hospital mortality compared with BMS. This outcome benefit was seen across subgroups in various subgroups including elderly, diabetics, and acute myocardial infarction as well as multivessel interventions.

Balloon mitral valvuloplasty in the United States: a 13-year perspective.

BACKGROUND: Incidence and prevalence of mitral stenosis is declining in the US. We performed this study to determine recent trends in utilization, complications, mortality, length of stay, and cost associated with balloon mitral valvuloplasty. METHODS: Utilizing the nationwide inpatient sample database from 1998 to 2010, we identified patients using the International Classification of Diseases, 9th Revision, Clinical Modification procedure code for "percutaneous valvuloplasty." Patients ≥18 years of age with mitral stenosis were included. Patients with concomitant aortic, tricuspid, or pulmonic stenosis were excluded. Primary outcome included death and procedural complications. RESULTS: A total of 1308 balloon mitral valvuloplasties (weighted n = 6540) were analyzed. There was a 7.5% decrease in utilization of the procedure from 24.6 procedures/10 million population in 1998-2001 to 22.7 procedures/10 million population in 2008-2010 (P for trend = .098). We observed a 15.9% overall procedural complication rate and 1.7% mortality rate. The procedural complication rates have increased in recent years (P = .001), corresponding to increasing age and burden of comorbidities in patients. The mean cost per admission for balloon mitral valvuloplasty has gone up significantly over the 10 years, from $11,668 ± 1046 in 2001 to $23,651 ± 301 in 2010 (P <.001). CONCLUSIONS: In a large cross-sectional study of balloon mitral valvuloplasty in the US, we have reported trends of decreasing overall utilization and increasing procedural complication rates and cost over a period of 13 years.

Influence of left ventricular remodeling on atrial fibrillation recurrence and cardiovascular hospitalizations in patients undergoing rhythm-control therapy.

BACKGROUND: Atrial fibrillation (AF) patients with left ventricular hypertrophy (LVH) and diastolic dysfunction may derive benefit from being in sinus rhythm but no data are available to support this strategy in them. We sought to investigate effect of left ventricular remodeling on cardiovascular outcomes in AF patients undergoing rhythm control strategy. METHODS: We identified 1088 patients with echocardiographic data on left ventricular mass (LVM) enrolled in the AFFIRM trial. Using the American Society of Echocardiography (ASE) criteria, patients were divided into 4 categories: 1) normal geometry, 2) concentric remodeling, 3) eccentric hypertrophy, and 4) concentric hypertrophy. The primary endpoint was AF recurrence and the secondary endpoint was cardiovascular hospitalization (CVH). RESULTS: In rhythm control arm, median time to recurrence in patients with concentric LVH was 13.3 months (95% CI 8.2-24.5) vs. 28.3 months (95% CI 20.2-48.6) in patients without LVH. Concentric left ventricular hypertrophy (LVH) was independently predictive of AF recurrence (HR 1.49, 95% CI 1.10-2.01, p=0.01) in rhythm control arm, but not in overall population or rate control arm. Both concentric and eccentric LVH were independently predictive of cardiovascular hospitalization (CVH) in the overall population, with respective HRs of 1.36 (1.04-1.78, p=0.03) and 1.38 (1.02-1.85, p=0.04). CONCLUSION: Concentric LVH is predictive of AF recurrences when a predominantly pharmacologic rhythm-control strategy is employed. Different patterns of LVH seem to be important determinants of outcomes (AF recurrence and CVH). These findings may have important clinical implications for the management of patients with AF and LVH. Further studies are warranted to confirm our findings.

Percutaneous aortic balloon valvotomy in the United States: a 13-year perspective.

BACKGROUND: We determined the contemporary trends of percutaneous aortic balloon valvotomy and its outcomes using the nation's largest hospitalization database. There has been a resurgence in the use of percutaneous aortic balloon valvotomy in patients at high surgical risk because of the development of less-invasive endovascular therapies. METHODS: This is a cross-sectional study with time trends using the Nationwide Inpatient Sample database between the years 1998 and 2010. We identified patients using the International Classification of Diseases, 9th Revision, Clinical Modification procedure code for valvotomy. Only patients aged more than 60 years with aortic stenosis were included. Primary outcome included in-hospital mortality, and secondary outcomes included procedural complications and length of hospital stay. RESULTS: A total of 2127 percutaneous aortic balloon valvotomies (weighted n = 10,640) were analyzed. The use rate of percutaneous aortic balloon valvotomy increased by 158% from 12 percutaneous aortic balloon valvotomies per million elderly patients in 1998-1999 to 31 percutaneous aortic balloon valvotomies per million elderly patients in 2009-2010 in the United States (P < .001). The hospital mortality decreased by 23% from 11.5% in 1998-1999 to 8.8% in 2009-2010 (P < .001). Significant predictors of in-hospital mortality were the presence of increasing comorbidities (P = .03), unstable patient (P < .001), any complication (P < .001), and weekend admission (P = .008), whereas increasing operator volume was associated with significantly reduced mortality (P = .03). Patients who were admitted to hospitals with the highest procedure volume and the highest volume operators had a 51% reduced likelihood (P = .05) of in-hospital mortality when compared with those in hospitals with the lowest procedure volume and lowest volume operators. CONCLUSION: This study comprehensively evaluates trends for percutaneous aortic balloon valvotomy in the United States and demonstrates the significance of operator and hospital volume on outcomes.

Outcomes in atrial fibrillation patients with and without left ventricular hypertrophy when treated with a lenient rate-control or rhythm-control strategy.

Although left ventricular (LV) hypertrophy has been proposed as a factor predisposing to atrial fibrillation (AF), its relevance to prognosis and selection of therapeutic strategies is unclear. We identified 2,105 patients with echocardiographic data on LV mass enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. LV hypertrophy was defined as increased LV mass, stratified by American Society of Echocardiography criteria. The primary end point was all-cause mortality, secondary end point was as per AFFIRM trial definition, and tertiary end point was cardiovascular hospitalizations. We compared "strict" versus "lenient" rate control in patients with increased LV mass, and studied association of heart failure (HF) with preserved and decreased systolic function in patients with increased LV mass. Over 6 years, 332 deaths (15.7%) were reported. Adjusted hazard ratio (HR) of severely increased LV mass for all-cause mortality was 1.34 (95% confidence interval [CI] 1.01 to 1.79, p=0.045) for the overall population and 1.61 (95% CI 1.09 to 2.37, p=0.016) for the rhythm-control arm. Increased LV mass was a predictor of cardiovascular hospitalizations in the lenient rate-control group (HR 1.72, 95% CI 1.05 to 2.82, p=0.03) but not in the strict rate-control group. Severely increased LV mass was predictive of cardiovascular hospitalizations in patients with HF with preserved (HR 1.8, 95% CI 1.0 to 3.2, p=0.03) and decreased LV systolic function (HR 2.4, 95% CI 1.1 to 5.2, p=0.02). Thus, LV hypertrophy is a significant independent predictor of mortality in patients with AF, especially those managed with rhythm control. In patients with LV hypertrophy, strict rate control may be associated with better outcomes than lenient rate control. LV hypertrophy portends higher cardiovascular morbidity in patients with AF and HF.

Cerebral protection against left ventricular thrombus during transcatheter aortic valve replacement in a patient with critical aortic stenosis.

Transcatheter aortic valve replacement is an increasingly common treatment of critical aortic stenosis. Many aortic stenosis patients have concomitant left ventricular dysfunction, which can instigate the formation of thrombus resistant to anticoagulation. Recent trials evaluating transcatheter aortic valve replacement have excluded patients with left ventricular thrombus. We present a case in which an 86-year-old man with known left ventricular thrombus underwent successful transcatheter aortic valve replacement under cerebral protection.

QRS duration on electrocardiography and cardiovascular mortality (from the National Health and Nutrition Examination Survey-III).

The relation of bundle branch block (BBB) with adverse outcome is controversial. We hypothesized that increased QRS duration is an independent predictor of cardiovascular (CV) mortality in a cross-sectional US population. This is a retrospective cohort study on prospectively collected data to assess the relationship between QRS duration on routine ECG and CV mortality. Participants included 8,527 patients with ECG data available from the National Health and Nutrition Examination Survey data set, representing 74,062,796 individuals in the United States. Mean age was 60.5 ± 13.6 years. Most subjects were white (87%) and women (53%). During the follow-up period of 106,244.6 person-years, 1,433 CV deaths occurred. Multivariate analysis revealed that the highest quartile of QRS duration was associated with higher CV mortality than lowest quartile (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.01 to 1.7, p = 0.04) after adjustment for established risk factors. Both left BBB (HR 2.4, 95% CI 1.3 to 4.7, p = 0.009) and right BBB (HR 1.90, 95% CI 1.2 to 3.0, p = 0.008) were significantly associated with increased CV mortality. The addition of the QRS duration in 10-millisecond increments to the Framingham Risk Score model resulted in 4.4% overall net reclassification improvement (95% CI 0.02 to 0.04; p = 0.00006). In conclusion, increased QRS duration was found to be an independent predictor of CV mortality in this cross-sectional US population. A model including QRS duration in addition to traditional risk factors was associated with improved CV risk prediction.

ST-T wave abnormality in lead aVR and reclassification of cardiovascular risk (from the National Health and Nutrition Examination Survey-III).

Electrocardiographic lead aVR is often ignored in clinical practice. The aim of this study was to investigate whether ST-T wave amplitude in lead aVR predicts cardiovascular (CV) mortality and if this variable adds value to a traditional risk prediction model. A total of 7,928 participants enrolled in the National Health and Nutrition Examination Survey (NHANES) III with electrocardiographic data available were included. Each participant had 13.5 ± 3.8 years of follow-up. The study sample was stratified according to ST-segment amplitude and T-wave amplitude in lead aVR. ST-segment elevation (>8 µV) in lead aVR was predictive of CV mortality in the multivariate analysis when not accounting for T-wave amplitude. The finding lost significance after including T-wave amplitude in the model. A positive T wave in lead aVR (>0 mV) was the strongest multivariate predictor of CV mortality (hazard ratio 3.37, p <0.01). The addition of T-wave amplitude in lead aVR to the Framingham risk score led to a net reclassification improvement of 2.7% of subjects with CV events and 2.3% of subjects with no events (p <0.01). Furthermore, in the intermediate-risk category, 20.0% of the subjects in the CV event group and 9.1% of subjects in the no-event group were appropriately reclassified. The absolute integrated discrimination improvement was 0.012 (p <0.01), and the relative integrated discrimination improvement was 11%. In conclusion, T-wave amplitude in lead aVR independently predicts CV mortality in a cross-sectional United States population. Adding T-wave abnormalities in lead aVR to the Framingham risk score improves model discrimination and calibration with better reclassification of intermediate-risk subjects.