ABC | Volume 115, Nº1, July 2020

Original Article Pessoa et al. Cost-effectiveness comparison between drug-eluting stents and bare-metal stents Arq Bras Cardiol. 2020; 115(1):80-89 Cost-effectiveness Analysis The costs of the procedure and the effectiveness of each stent were calculated according to the type of stent implanted (DES or BMS). BMS had a cost of R$ 4,085.21 and DES of R$ 5,722.21. Considering the occurrence of ISR, DESs were 8.7% more effective than BMSs, with an ICER of R$ 18,816.09. Regarding TLR, DESs were 5.9% more effective than BMSs, with an ICER of R$ 27,745.76. Discussion Population Analysis In the present study, as previously reported in the literature, 13,14  there was no difference between the use of DESs and BMSs in major adverse events (death, AMI, thrombosis), but a significant difference was observed in restenosis (DES: 1.4 % vs BMS: 10.1%; p = 0.018). The rate of TLR in 1 year was 1.4% in the DES group and 7.3% in the BMS group (p = 0.058). In this study, the only documented case of thrombosis occurred in the DES group (0.0% vs. 0.74%; p = 0.65), but without statistical significance. In accordance with national and international guidelines for PCI, 15,1 6  the use of radial access minimized the occurrence of bleeding, with no major bleeding requiring blood transfusion or surgical intervention. Although small- diameter vessels, long lesions and diabetes mellitus are risk factors for restenosis, 17   this was not confirmed in the present study. Presence of diabetes did not differ between the 2 groups (DES: 31.0% and BMS: 27.7%; p = 0.59). Of patients with ISR, 40.0% had diabetes; however, 27.7% of patients who did not develop ISR also had diabetes, with no statistical significance (p = 0.22) (Table 5). Regarding lesion length, lesions <20 mm were found in 60.0% of patients with ISR and in 56.6% of patients without ISR, without statistical significance (p = 0.8). Therefore, the only independent predictor of restenosis was the use of a BMS (RR: 8.14; 95% CI: 1.05-63.2; p = 0.045), where 93.3% of ISR cases occurred in patients who received a BMS. Table 5 - Clinical variables and comorbidities according to the ISR outcome Clinical variables WITH ISR WITHOUT ISR p-value Mean age (years) ± SD 59.9 ± 8.4 61.9 ± 10.1 0.45 * Male sex n (%) 9 60.0 127 64.8 0.71 White color n (%) 10 66.7 128 69.6 0.51 Comorbidities n (%) Hypertension 13 86.7 156 79.6 0.39 Obesity 4 26.7 44 23.0 0.74 Diabetes mellitus 6 40 54 27.6 0.22 Dyslipidemia 8 53.3 106 54.9 0.91 Smoking 3 20.0 38 19.8 0.079 Smoking (ex + current) 13 86.7 116 60.4 0.043 Family history 9 64.3 116 60.4 0.77 Previous AMI 3 20.0 24 12.4 0.30 CRF 0 0 6 3.1 0.64 Hemodialysis 0 0 2 1.03 0.86 EF <40% 0 0 16 8.9 0.26 Silent ischemia 1 6.7 3 1.6 0.26 Stable angina 2 13.3 66 35.1 0.086 Unstable angina 8 53.3 67 35.1 0.16 NSTEMI 3 21.4 21 11.1 0.22 STEMI 1 7.1 40 20.8 0.19 Categoricaldatawereexpressedas frequency(n)andpercentage(%)andcomparedby  theX 2  testorFisher’sexact test.Datawithnormaldistributionwereexpressedas mean ± standard deviation and compared by Student's t test * for independent samples. Legend: ISR -  in-stent restenosis; SD - standard deviation; EF -  ejection fraction; AMI - acute myocardial infarction; CRF - chronic renal failure; STEMI: ST-segment elevation myocardial infarction; NSTEMI: non-ST-segment elevation myocardial infarction. Source: The Author, 2018. 86