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Long Term Clinical Outcomes Following Drug-Eluting and Bare Metal Stenting in Massachusetts. Laura Mauri, MD, MSc; Treacy Silverstein, B.Sc.; Ann Lovett, R.N., M.A.; Frederic S. Resnic, M.D., M.Sc.; and Sharon-Lise T. Normand, Ph.D. Brigham and Women’s Hospital, Harvard Medical School,
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Long Term Clinical Outcomes Following Drug-Eluting and Bare Metal Stenting in Massachusetts Laura Mauri, MD, MSc; Treacy Silverstein, B.Sc.; Ann Lovett, R.N., M.A.; Frederic S. Resnic, M.D., M.Sc.; and Sharon-Lise T. Normand, Ph.D. Brigham and Women’s Hospital, Harvard Medical School, Harvard School of Public Health Boston, Massachusetts Study funding from Massachusetts Department of Public Health November 4, 2007 American Heart Association Scientific Sessions
Drug-Eluting and Bare Metal Stenting in MassachusettsBackground • The data reported for available DES in the US indicate that these devices are important advancements by reducing the need for revascularization • Long term clinical outcomes remain uncertain following DES use compared to BMS use in the general population
Drug-Eluting and Bare Metal Stenting in MassachusettsBackground • Randomized trials of DES have been limited in power to detect rare events and in generalizability to a broad range of practice patterns and patient populations • Observational studies have been limited by possible residual selection bias and incomplete follow-up • Studies comparing DES and BMS use have been performed in populations with restricted DES use
Drug-Eluting and Bare Metal Stenting in MassachusettsObjectives • To evaluate whether the use of DES is associated with increased rates of death or MI compared with BMS in general use representative of current US practice • To confirm whether the use of DES is associated with reduction in revascularization compared with BMS in general use representative of current US practice
Drug-Eluting and Bare Metal Stenting in MassachusettsMethods: Data source Mass-DAC • All PCI in Massachusetts (>25000 stent procedures per year) • Massachusetts Dept. of Public Health mandatory reporting • Clinical and procedural factors collected prospectively using ACC NCDR instrument • Mortality from hospital record, Mass. vital statistics and Social Security website • Myocardial infarction and revascularization from Mass-DAC PCI and CABG data merged with hospital discharge data • Index procedures performed April 2003 – September 2004 • Non-Massachusetts residents excluded
Drug-Eluting and Bare Metal Stenting in MassachusettsMethods: Propensity Score Matched Analysis • Patients assigned to DES or BMS groups based on treatment at index procedure • Propensity score matching • Logistic regression to predict DES treatment by patient, procedural, hospital variables • Caliper matching of DES to BMS patients • Primary outcomes: Matched risk differences for mortality, myocardial infarction and revascularization rates at 2 years • Paired t-test, 2-sided alpha 0.05
Drug-Eluting and Bare Metal Stenting in Massachusetts N=21,019 PCI Patients in Massachusetts April 1, 2003- September 30, 2004 Complete 2 year follow-up 1,538 non-residents excluded 564 adminstrative files not linkable N=18,917 PCI Patients 1,191 patients with both stent types excluded N=11,516 DES Only Patients N=6,210 BMS Only Patients 7
35% BMS 65% DES 72% sirolimus, 28% paclitaxel eluting stents
Drug-Eluting and Bare Metal Stenting in MassachusettsPatient Characteristics before Match
Drug-Eluting and Bare Metal Stenting in MassachusettsPatient Characteristics before Match
Drug-Eluting and Bare Metal Stenting in MassachusettsProcedure Indications before Match
Drug-Eluting and Bare Metal Stenting in MassachusettsProcedural Characteristics before Match
Revascularization Mortality MI P < 0.0001 P < 0.0001 P < 0.0001 24.0% 20.0% 12.4% 12.1% 9.1% 6.7% DES (n=2297/11516) BMS (n=1488/6210) DES (n=769/11516) BMS (n=768/6210) DES (n=1049/11516) BMS (n=754/6210) Drug-Eluting and Bare Metal Stenting in Massachusetts, Unadjusted 2-Year Outcomes
n=5441 DES n=5441 BMS Propensity matched pairs 63 variables
Drug-Eluting and Bare Metal Stenting in MassachusettsPatient Characteristics after Match *%SD = Percent Standardized Difference Values <10% reflect well-matched characteristics
Drug-Eluting and Bare Metal Stenting in MassachusettsPatient Characteristics after Match *%SD = Percent Standardized Difference Values <10% reflect well-matched characteristics
Drug-Eluting and Bare Metal Stenting in MassachusettsProcedure Characteristics after Match *%SD = Percent Standardized Difference Values <10% reflect well-matched characteristics
Drug-Eluting and Bare Metal Stenting in MassachusettsProcedural Characteristics after Match *%SD = Percent Standardized Difference Values <10% reflect well-matched characteristics
Revascularization Mortality MI P < 0.0001 P < 0.0001 P = 0.11 23.9% 20.1% 11.9% 11.8% 10.8% 9.4% BMS (n=1303/5441) DES (n=1095/5441) DES (n=514/5441) BMS (n=647/5441) DES (n=590/5441) BMS (n=643/5441) Drug-Eluting and Bare Metal Stenting in Massachusetts, Primary ResultsPropensity Matched 2-Year Outcomes D = -2.4% [-3.6,-1.3] D = -1.0% [-2.2,+0.2] D = -3.8% [-5.4,-2.3]
DES n=5,441 30% BMS n=5,441 11.9% Cumulative Incidence 20% 9.4% 10% 0% 0 180 365 730 Drug-Eluting and Bare Metal Stenting in Massachusetts 2-Year Outcome in Matched Patients Mortality Time after Initial Procedure (days)
DES n=5,441 30% BMS n=5,441 Cumulative Incidence 20% 10% 0% 0 180 365 730 Drug-Eluting and Bare Metal Stenting in Massachusetts 2-Year Outcome in Matched Patients MI 12.3% 11.2% Time after Initial Procedure (days)
DES n=5,441 30% BMS n=5,441 25.1% Cumulative Incidence 20% 20.9% 10% 0% 0 180 365 730 Drug-Eluting and Bare Metal Stenting in Massachusetts 2-Year Outcome in Matched Patients Revascularization Time after Initial Procedure (days)
Risk Difference (95% CI) Favors DES Favors BMS 5% -5% 0 Drug-Eluting and Bare Metal Stenting in Massachusetts Matched Risk Differences at 2 years Mortality • = -2.4% [-3.6,-1.3] p<0.0001 DES 9.4% BMS 11.9% Myocardial Infarction • = -1.0% [-2.2,+0.2] p=0.11 DES 10.8% BMS 11.3% Revascularization • = -3.8% [-5.4,-2.3] p<0.0001 DES 20.1% BMS 23.9%
Drug-Eluting and Bare Metal Stenting in Massachusetts Sensitivity analyses • Effect of differential rates of use of DES vs BMS over time • 2 day mortality difference
n=3752 DES n=3752 BMS Propensity matched pairs adjusted for time on market
Revascularization Mortality MI P = 0.040 P < 0.0001 P = 0.052 22.9% 20.9% 11.7% 11.8% 10.8% 8.5% DES (n=784/3752) BMS (n=858/3752) DES (n=318/3752) BMS (n=439/3752) DES (n=370/3752) BMS (n=422/3752) Drug-Eluting and Bare Metal Stenting in Massachusetts Sensitivity Analysis 2-Year Outcomes adjusted for time on market D = -3.2% [-4.6,-1.8] D = -1.4% [-2.8,0.0] D = -1.9% [-3.9,-0.1]
Drug-Eluting and Bare Metal Stenting in Massachusetts Sensitivity analyses • Adjustment for time on market is consistent with results of the primary analysis • larger observed difference favoring DES for mortality • 2 day mortality difference after propensity match is small • 2 day mortality 0.4% vs 0.8% (DES vs BMS) • D = -0.4% at 2d vs D = -2.4% at 2 y
Drug-Eluting and Bare Metal Stenting in Massachusetts Comparison with PCI Practice Patterns and Other Studies Distinguishing features: high rate of PCI/population, high rate of DES/procedure, study sample chosen to start with introduction of DES and to end when all patients had complete 2 year follow up. 1. Lagerqvist B et al. N Engl J Med 2007;356:1009-19. 2. Jensen, LO et al. JACC2007;50(5):463-70. 3.Tu J et al. NEJM 2007;357:1393-42.
Drug-Eluting and Bare Metal Stenting in MassachusettsConclusions From the Massachusetts state dataset of 21,024 PCI unique patient procedures in Massachusetts from April 2003- September 2004 with complete 2y follow-up, propensity matched analysis of 10,882 patients demonstrated: • No increase in rates of death, or myocardial infarction associated with DES as compared to BMS use at 2 years. • A significantly lower mortality rate was observed for DES at 2 years, and will be monitored as follow up proceeds to 3-5 years • A lower rate of revascularization in patients treated with DES compared with BMS.