2021
Sex Differences in Procedural Outcomes Among Patients Undergoing Left Atrial Appendage Occlusion
Darden D, Duong T, Du C, Munir MB, Han FT, Reeves R, Saw J, Zeitler EP, Al-Khatib SM, Russo AM, Minges KE, Curtis JP, Freeman JV, Hsu JC. Sex Differences in Procedural Outcomes Among Patients Undergoing Left Atrial Appendage Occlusion. JAMA Cardiology 2021, 6: 1275-1284. PMID: 34379072, PMCID: PMC8358791, DOI: 10.1001/jamacardio.2021.3021.Peer-Reviewed Original ResearchConceptsHospital adverse eventsMajor adverse eventsAdverse eventsAtrial appendage occlusionMajor bleedingPericardial effusionAppendage occlusionAtrial fibrillationSex differencesCongestive heart failureCoronary artery diseaseAdjusted logistic regression analysisParoxysmal atrial fibrillationLogistic regression analysisMultivariable adjusted logistic regression analysesPrior strokeUncontrolled hypertensionHospital outcomesHospital stayMultivariable adjustmentProlonged hospitalBaseline characteristicsCohort studySelect patientsArtery diseasePrognosis of Claims‐ Versus Trial‐Based Ischemic and Bleeding Events Beyond 1 Year After Coronary Stenting
Butala NM, Faridi KF, Secemsky EA, Song Y, Curtis J, Gibson CM, Kazi D, Shen C, Yeh RW. Prognosis of Claims‐ Versus Trial‐Based Ischemic and Bleeding Events Beyond 1 Year After Coronary Stenting. Journal Of The American Heart Association 2021, 10: e018744. PMID: 33682431, PMCID: PMC8174225, DOI: 10.1161/jaha.120.018744.Peer-Reviewed Original ResearchConceptsUnadjusted mortality ratesIschemic eventsDAPT studyMortality rateEnd pointCox proportional hazards modelPercutaneous coronary interventionProportional hazards modelCardiovascular clinical trialsTrial adjudicationBleeding eventsCathPCI RegistryCoronary interventionCoronary stentingSimilar prognosisPrognostic significanceClinical eventsClinical trialsMedicare claimsAdministrative claimsMortality riskHazards modelPatientsPrognosisDeath
2020
Periprocedural Risk and Survival Associated With Implantable Cardioverter-Defibrillator Placement in Older Patients With Advanced Heart Failure
Fudim M, Ali-Ahmed F, Parzynski CS, Ambrosy AP, Friedman DJ, Pokorney SD, Curtis JP, Fonarow GC, Masoudi FA, Hernandez AF, Al-Khatib SM. Periprocedural Risk and Survival Associated With Implantable Cardioverter-Defibrillator Placement in Older Patients With Advanced Heart Failure. JAMA Cardiology 2020, 5: 643-651. PMID: 32211811, PMCID: PMC7097837, DOI: 10.1001/jamacardio.2020.0391.Peer-Reviewed Original ResearchConceptsAdvanced heart failureAdvanced HF populationHeart transplant listingPeriprocedural complication rateHeart failureSudden cardiac deathComparator groupVentricular assist deviceInotrope useTransplant listingCardiac deathComplication rateHF populationPrimary preventionCardiac arrestNew York Heart Association class IV symptomsNational Cardiovascular Data Registry ICD RegistryAssist deviceLeft ventricular ejection fractionImplantable cardioverter-defibrillator placementAdvanced HF groupClass IV symptomsFirst-time ICDLeft ventricular assist deviceNYHA class II
2019
Modeling defibrillation benefit for survival among cardiac resynchronization therapy defibrillator recipients
Bilchick KC, Wang Y, Curtis JP, Cheng A, Dharmarajan K, Shadman R, Dardas TF, Anand I, Lund LH, Dahlström U, Sartipy U, Maggioni A, O'Connor C, Levy WC. Modeling defibrillation benefit for survival among cardiac resynchronization therapy defibrillator recipients. American Heart Journal 2019, 222: 93-104. PMID: 32032927, PMCID: PMC7814502, DOI: 10.1016/j.ahj.2019.12.017.Peer-Reviewed Original ResearchConceptsCRT-D patientsImplantable cardioverter defibrillatorSurvival benefitCRT-DsCardiac resynchronization therapy defibrillator recipientsCardiac resynchronization therapy candidatesSeattle Heart Failure ModelSeattle Proportional Risk ModelCox proportional hazards regressionNational Cardiovascular Data RegistryHeart Failure TrialHeart failure patientsProportional hazards regressionHeart failure modelProportional risk modelFailure patientsCRT candidatesHeart failureCRT pacemakerFailure TrialArrhythmic deathHazards regressionDefibrillator recipientsCRT deviceCardioverter defibrillatorAssociation of Physician Specialty With Long-Term Implantable Cardioverter-Defibrillator Complication and Reoperations Rates
Chui PW, Wang Y, Ranasinghe I, Mitiku TY, Seto AH, Rosman L, Lampert R, Minges KE, Enriquez AD, Curtis JP. Association of Physician Specialty With Long-Term Implantable Cardioverter-Defibrillator Complication and Reoperations Rates. Circulation Cardiovascular Quality And Outcomes 2019, 12: e005374. PMID: 31185734, PMCID: PMC7412734, DOI: 10.1161/circoutcomes.118.005374.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overClinical CompetenceDefibrillators, ImplantableElectric CountershockFee-for-Service PlansFemaleHumansIncidenceMaleMedicarePostoperative ComplicationsPractice Patterns, Physicians'RegistriesReoperationRisk AssessmentRisk FactorsSpecializationTime FactorsTreatment OutcomeUnited StatesConceptsLong-term device-related complicationsDevice-related complicationsICD implantationLong-term outcomesPhysician specialtyGeneral cardiologistsThoracic surgeonsHigh riskNational Cardiovascular Data Registry ICD RegistryLong-term adverse outcomesImplantable cardioverter defibrillator implantationPhysician specialty trainingCardioverter-defibrillator implantationCumulative incidence rateCase-mix adjusted ratesReoperation rateBackground PatientsConclusions PatientsICD RegistryPrimary outcomeAdverse outcomesIncidence rateInterventional cardiologistsAdjusted ratesReoperation
2018
Ventricular septal rupture complicating acute myocardial infarction: Incidence, treatment, and outcomes among medicare beneficiaries 1999–2014
Goldsweig AM, Wang Y, Forrest JK, Cleman MW, Minges KE, Mangi AA, Aronow HD, Krumholz HM, Curtis JP. Ventricular septal rupture complicating acute myocardial infarction: Incidence, treatment, and outcomes among medicare beneficiaries 1999–2014. Catheterization And Cardiovascular Interventions 2018, 92: 1104-1115. PMID: 29513365, DOI: 10.1002/ccd.27576.Peer-Reviewed Original ResearchConceptsAcute myocardial infarctionVentricular septal ruptureTimely primary PCIMortality ratePrimary PCIPercutaneous repairSeptal ruptureMyocardial infarctionRetrospective cohort studyUnadjusted mortality ratesUnrepaired patientsVSR repairFatal complicationCohort studyAnnual incidenceMedicare feeService beneficiariesPatientsIncidenceStudy periodMortalityHospitalizationInfarctionRepairPCIIncidence and Predictors of Perioperative Complications With Transvenous Lead Extractions
Sood N, Martin DT, Lampert R, Curtis JP, Parzynski C, Clancy J. Incidence and Predictors of Perioperative Complications With Transvenous Lead Extractions. Circulation Arrhythmia And Electrophysiology 2018, 11: e004768. PMID: 29453324, DOI: 10.1161/circep.116.004768.Peer-Reviewed Original ResearchConceptsTransvenous lead extractionMajor perioperative complicationsUrgent cardiac surgeryPerioperative complicationsLead extractionCardiac surgeryMajor complicationsClinical statusNational Cardiovascular Data Registry Implantable Cardioverter Defibrillator RegistryImplantable Cardioverter-Defibrillator RegistryRecent single-center studiesMultivariable logistic regression analysisHigh-voltage leadsReal-world incidenceSingle-center studyImplantable cardioverter-defibrillator leadsPatient's clinical statusHigh-volume centersRisk of complicationsLogistic regression analysisCardiovascular implantable electronic devicesCardioverter-defibrillator leadsReal-world outcomesImplantable electronic devicesFemale sexComparison of Physician Visual Assessment With Quantitative Coronary Angiography in Assessment of Stenosis Severity in China
Zhang H, Mu L, Hu S, Nallamothu BK, Lansky AJ, Xu B, Bouras G, Cohen DJ, Spertus JA, Masoudi FA, Curtis JP, Gao R, Ge J, Yang Y, Li J, Li X, Zheng X, Li Y, Krumholz HM, Jiang L. Comparison of Physician Visual Assessment With Quantitative Coronary Angiography in Assessment of Stenosis Severity in China. JAMA Internal Medicine 2018, 178: 239-247. PMID: 29340571, PMCID: PMC5838612, DOI: 10.1001/jamainternmed.2017.7821.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overChinaCoronary AngiographyCoronary StenosisCoronary VesselsCross-Sectional StudiesFemaleFollow-Up StudiesHumansIncidenceMaleMiddle AgedPercutaneous Coronary InterventionPractice Patterns, Physicians'Predictive Value of TestsProspective StudiesRisk AssessmentSeverity of Illness IndexTime FactorsConceptsPhysician visual assessmentPercutaneous coronary interventionAcute myocardial infarctionQuantitative coronary angiographyStenosis severityCoronary angiographyMean agePCI studiesMean percent diameter stenosisIndependent core laboratoryPercent diameter stenosisCross-sectional studyNon-AMI patientsStandard clinical practiceFractional flow reserveSubset of participantsQCA assessmentCoronary revascularizationMore stenosisCoronary interventionCoronary lesionsChina PatientCoronary angiogramDiameter stenosisMyocardial infarction
2017
Complications Associated With Implantable Cardioverter Defibrillators in Adults With Congenital Heart Disease or Left Ventricular Noncompaction Cardiomyopathy (From the NCDR® Implantable Cardioverter-Defibrillator Registry)
Gleva MJ, Wang Y, Curtis JP, Berul CI, Huddleston CB, Poole JE. Complications Associated With Implantable Cardioverter Defibrillators in Adults With Congenital Heart Disease or Left Ventricular Noncompaction Cardiomyopathy (From the NCDR® Implantable Cardioverter-Defibrillator Registry). The American Journal Of Cardiology 2017, 120: 1891-1898. PMID: 28917495, DOI: 10.1016/j.amjcard.2017.07.103.Peer-Reviewed Original ResearchConceptsCongenital heart diseaseComplication rateVentricular noncompaction cardiomyopathyHeart diseaseHospital complicationsEbstein's anomalyCardiac resynchronizationSeptal defectNoncompaction cardiomyopathyImplantable cardioverter defibrillator implantationDual chamberAcute lead dislodgmentsSingle-chamber ICDCardioverter-defibrillator implantationPeriprocedural complication rateGreater complication rateVentricular septal defectTetralogy of FallotAtrial septal defectImplantable cardioverter defibrillatorChildhood heart diseaseSingle-chamber devicesChi-square testHospital deathAdult patientsSeattle Heart Failure and Proportional Risk Models Predict Benefit From Implantable Cardioverter-Defibrillators
Bilchick KC, Wang Y, Cheng A, Curtis JP, Dharmarajan K, Stukenborg GJ, Shadman R, Anand I, Lund LH, Dahlström U, Sartipy U, Maggioni A, Swedberg K, O’Conner C, Levy WC. Seattle Heart Failure and Proportional Risk Models Predict Benefit From Implantable Cardioverter-Defibrillators. Journal Of The American College Of Cardiology 2017, 69: 2606-2618. PMID: 28545633, PMCID: PMC5502749, DOI: 10.1016/j.jacc.2017.03.568.Peer-Reviewed Original ResearchConceptsSeattle Heart Failure ModelSeattle Proportional Risk ModelNational Cardiovascular Data RegistryPrimary prevention ICDsHeart failureSudden deathCause mortalitySurvival benefitMultivariable Cox proportional hazards regressionCox proportional hazards regressionProportional riskProportional hazards regressionRecent clinical trialsHeart failure modelProportional risk modelControl patientsOverall survivalVentricular arrhythmiasHazards regressionICD benefitClinical trialsCardioverter defibrillatorLarge cohortHigh riskData registry
2015
National Trends in Pulmonary Embolism Hospitalization Rates and Outcomes for Adults Aged ≥65 Years in the United States (1999 to 2010)
Minges KE, Bikdeli B, Wang Y, Kim N, Curtis JP, Desai MM, Krumholz HM. National Trends in Pulmonary Embolism Hospitalization Rates and Outcomes for Adults Aged ≥65 Years in the United States (1999 to 2010). The American Journal Of Cardiology 2015, 116: 1436-1442. PMID: 26409636, PMCID: PMC4841688, DOI: 10.1016/j.amjcard.2015.07.068.Peer-Reviewed Original ResearchConceptsHospitalization ratesMortality rateReadmission ratesBlack patientsPrincipal discharge diagnosis codeOlder adultsCause readmission rateHospital mortality rateProportion of patientsRetrospective cohort studyDischarge diagnosis codesSkilled nursing facilitiesNational trendsSignificant racial differencesHigh rateHome health careHospital stayAdults AgedCohort studyMore patientsTherapeutic advancesDiagnosis codesMedicare feeNursing facilitiesSignificant burdenImpact of Hospital Volume on Outcomes of Lower Extremity Endovascular Interventions (Insights from the Nationwide Inpatient Sample [2006 to 2011])
Arora S, Panaich SS, Patel N, Patel N, Lahewala S, Solanki S, Patel P, Patel A, Manvar S, Savani C, Tripathi B, Thakkar B, Jhamnani S, Singh V, Patel S, Patel J, Bhimani R, Mohamad T, Remetz MS, Curtis JP, Attaran RR, Grines C, Mena CI, Cleman M, Forrest J, Badheka AO. Impact of Hospital Volume on Outcomes of Lower Extremity Endovascular Interventions (Insights from the Nationwide Inpatient Sample [2006 to 2011]). The American Journal Of Cardiology 2015, 116: 791-800. PMID: 26100585, DOI: 10.1016/j.amjcard.2015.05.050.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAged, 80 and overEndovascular ProceduresFemaleFollow-Up StudiesHospital CostsHospital MortalityHospitals, High-VolumeHospitals, Low-VolumeHumansIncidenceInpatientsLower ExtremityMaleMiddle AgedPeripheral Arterial DiseasePostoperative ComplicationsPostoperative PeriodPrognosisRegistriesRetrospective StudiesUnited StatesYoung AdultConceptsPeripheral endovascular interventionsHospitalization costsEndovascular interventionInhospital mortalityAmputation rateHospital volumePrimary outcomeCharlson co-morbidity index scoreUtilization Project Nationwide Inpatient Sample databaseLower Extremity Endovascular InterventionsTwo-level hierarchical multivariateNationwide Inpatient Sample databaseHospital volume quartilesCo-morbidity statusHospital procedural volumeLower amputation ratesAppropriate International ClassificationHigh-volume centersAnnual institutional volumeWeekend admissionSecondary outcomesPostprocedural complicationsStudy cohortNinth RevisionVolume centersDefibrillator implantations for primary prevention in the United States: Inappropriate care or inadequate documentation: Insights from the National Cardiovascular Data ICD Registry
Kaiser DW, Tsai V, Heidenreich PA, Goldstein MK, Wang Y, Curtis J, Turakhia MP, Registry C. Defibrillator implantations for primary prevention in the United States: Inappropriate care or inadequate documentation: Insights from the National Cardiovascular Data ICD Registry. Heart Rhythm 2015, 12: 2086-2093. PMID: 25982720, PMCID: PMC4770888, DOI: 10.1016/j.hrthm.2015.05.010.Peer-Reviewed Original ResearchConceptsMulticenter Unsustained Tachycardia TrialMulticenter Automatic Defibrillator Implantation TrialICD RegistryPrimary preventionICD implantationInclusion criteriaNational Cardiovascular Data Registry ICD RegistryMultivariate analysisImplantable cardioverter defibrillator implantationAtrioventricular conduction diseaseFirst-time ICDPrimary prevention ICDsPrior cardiac transplantationHeart Failure TrialPrimary prevention trialsProportion of patientsCardioverter-defibrillator implantationAppropriate use criteriaSudden cardiac deathCardiac transplantationDefibrillator implantationMADIT-IIPatient characteristicsYounger patientsCardiac deathAntithrombotic Therapy and Outcomes After ICD Implantation in Patients With Atrial Fibrillation and Coronary Artery Disease: An Analysis From the National Cardiovascular Data Registry (NCDR)®
Ghanbari H, Nallamothu BK, Wang Y, Curtis JP. Antithrombotic Therapy and Outcomes After ICD Implantation in Patients With Atrial Fibrillation and Coronary Artery Disease: An Analysis From the National Cardiovascular Data Registry (NCDR)®. Journal Of The American Heart Association 2015, 4: e001331. PMID: 25637345, PMCID: PMC4345865, DOI: 10.1161/jaha.114.001331.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overAtrial FibrillationCoronary Artery DiseaseDefibrillators, ImplantableDrug Therapy, CombinationFemaleFibrinolytic AgentsHemorrhageHumansIncidenceMaleMedicareMiddle AgedPatient DischargePlatelet Aggregation InhibitorsRegistriesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeUnited StatesWarfarinConceptsImplantable cardioverter defibrillator implantationCardioverter-defibrillator implantationCoronary artery diseaseMajor adverse cardiovascular eventsNational Cardiovascular Data RegistryAdverse cardiovascular eventsDevice-related complicationsAntithrombotic agentsDefibrillator implantationArtery diseaseAtrial fibrillationAntithrombotic therapyBleeding riskCardiovascular eventsThromboembolic eventsNational Cardiovascular Data Registry Implantable Cardioverter Defibrillator RegistryImplantable Cardioverter-Defibrillator RegistryHigh bleeding riskCombination of DAHospital dischargeICD implantationPrimary outcomeData registryPatientsFibrillation
2014
Rates of and Factors Associated With Infection in 200 909 Medicare Implantable Cardioverter-Defibrillator Implants
Prutkin JM, Reynolds MR, Bao H, Curtis JP, Al-Khatib SM, Aggarwal S, Uslan DZ. Rates of and Factors Associated With Infection in 200 909 Medicare Implantable Cardioverter-Defibrillator Implants. Circulation 2014, 130: 1037-1043. PMID: 25081281, DOI: 10.1161/circulationaha.114.009081.Peer-Reviewed Original ResearchConceptsICD infectionImplantable cardioverter defibrillator implantImplantable cardioverter-defibrillator infectionIndirect patient identifiersPrevious valve surgeryPrevious valvular surgeryChronic lung diseaseCardioverter-defibrillator implantICD-9 codesService claims dataCardioverter-defibrillator infectionComorbidity burdenManufacturers' advisoriesValvular surgeryEarly reinterventionValve surgeryAdverse eventsHospital dischargeRenal failureICD RegistryCerebrovascular diseaseImplant complicationsLung diseaseBiventricular ICDsMedicare patientsIn-Hospital Complications Associated With Reoperations of Implantable Cardioverter Defibrillators
Steckman DA, Varosy PD, Parzynski CS, Masoudi FA, Curtis JP, Sauer WH, Nguyen DT. In-Hospital Complications Associated With Reoperations of Implantable Cardioverter Defibrillators. The American Journal Of Cardiology 2014, 114: 419-426. PMID: 24927972, DOI: 10.1016/j.amjcard.2014.05.010.Peer-Reviewed Original ResearchConceptsHospital complicationsComplication rateRepeat proceduresLead extractionICD proceduresMultivariable adjusted odds ratiosNational Cardiovascular Data RegistryInitial implantImplantable cardioverter-defibrillator (ICD) proceduresHierarchical multivariable logistic regressionHospital adverse eventsAdjusted odds ratioHigh complication rateMultivariable logistic regressionLarge national cohortImplantable cardioverter defibrillatorHospital deathAdverse eventsICD implantationPatient characteristicsNational cohortOdds ratioProcedural outcomesCardioverter defibrillatorHigh risk
2012
Bleeding and vascular complications at the femoral access site following percutaneous coronary intervention (PCI): an evaluation of hemostasis strategies.
Tavris DR, Wang Y, Jacobs S, Gallauresi B, Curtis J, Messenger J, Resnic FS, Fitzgerald S. Bleeding and vascular complications at the femoral access site following percutaneous coronary intervention (PCI): an evaluation of hemostasis strategies. Journal Of Invasive Cardiology 2012, 24: 328-34. PMID: 22781471.Peer-Reviewed Original ResearchConceptsVascular closure deviceFemoral access siteHemostasis strategyPercutaneous coronary interventionVascular complicationsComplication rateSafety profileAccess siteHierarchical multiple logistic regression analysisMultiple logistic regression analysisPercutaneous coronary intervention (PCI) proceduresVascular complication ratesReduced complication ratesGood safety profileFemoral artery occlusionCoronary intervention proceduresRepresentative observational studyLogistic regression analysisRegression analysisType of hemostasisArtery dissectionCathPCI RegistryArtery occlusionCardiac catheterizationCoronary interventionBleeding-Avoidance Strategies and Outcomes in Patients ≥80 Years of Age With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention (from the NCDR CathPCI Registry)
Dodson JA, Wang Y, Chaudhry SI, Curtis JP. Bleeding-Avoidance Strategies and Outcomes in Patients ≥80 Years of Age With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention (from the NCDR CathPCI Registry). The American Journal Of Cardiology 2012, 110: 1-6. PMID: 22475362, PMCID: PMC3666171, DOI: 10.1016/j.amjcard.2012.02.039.Peer-Reviewed Original ResearchConceptsPrimary percutaneous coronary interventionPrimary PCIBleeding-avoidance strategiesST-segment elevation myocardial infarctionElevation myocardial infarctionPercutaneous coronary interventionMyocardial infarctionCoronary interventionUndergoing primary percutaneous coronary interventionST-elevation myocardial infarctionDirect thrombin inhibitorVascular closure deviceYears of ageBleeding complicationsCathPCI RegistryMultivariable analysisRadial accessClosure deviceHigh riskBleedingPatientsThrombin inhibitorsInfarctionLow bleedingStudy period
2011
Elevated B-Type Natriuretic Peptide Is Associated With Increased In-Hospital Mortality or Cardiac Arrest in Patients Undergoing Implantable Cardioverter-Defibrillator Implantation
Wei S, Loyo-Berríos NI, Haigney MC, Cheng H, Pinnow EE, Mitchell KR, Beachy JH, Woodward AM, Wang Y, Curtis JP, Marinac-Dabic D. Elevated B-Type Natriuretic Peptide Is Associated With Increased In-Hospital Mortality or Cardiac Arrest in Patients Undergoing Implantable Cardioverter-Defibrillator Implantation. Circulation Cardiovascular Quality And Outcomes 2011, 4: 346-354. PMID: 21487093, DOI: 10.1161/circoutcomes.110.943621.Peer-Reviewed Original ResearchConceptsElevated BNP levelsHospital mortalityCardiac arrestBNP levelsICD implantationElevated B-type natriuretic peptide (BNP) levelsNational Cardiovascular Data Registry ICD RegistryB-type natriuretic peptide levelsElevated B-type natriuretic peptideIncreased In-Hospital MortalityB-type natriuretic peptideImplantable cardioverter defibrillator implantationBiventricular ICD implantationHigh BNP groupNatriuretic peptide levelsIn-Hospital MortalityCardioverter-defibrillator implantationHierarchical logistic regressionBNP measurementHospital deathPeriprocedural complicationsRenal dysfunctionComplication rateBNP groupHeart failure
2010
The Relation Between Hospital Procedure Volume and Complications of Cardioverter-Defibrillator Implantation From the Implantable Cardioverter-Defibrillator Registry
Freeman JV, Wang Y, Curtis JP, Heidenreich PA, Hlatky MA. The Relation Between Hospital Procedure Volume and Complications of Cardioverter-Defibrillator Implantation From the Implantable Cardioverter-Defibrillator Registry. Journal Of The American College Of Cardiology 2010, 56: 1133-1139. PMID: 20863954, DOI: 10.1016/j.jacc.2010.07.007.Peer-Reviewed Original ResearchConceptsAdverse eventsProcedure volumeImplantable Cardioverter-Defibrillator RegistryHospital adverse outcomesInitial ICD implantationCardioverter-defibrillator implantationHigh-volume hospitalsLow-volume hospitalsPatients' clinical characteristicsBetter clinical outcomesHospital procedure volumeVolume-outcome relationshipNCDR ICD RegistryClinical characteristicsICD implantationICD RegistryProcedural complicationsClinical outcomesAdverse outcomesHospital characteristicsBiventricular ICDsImplant volumeHospitalRepresentative populationICD