IJCS | Volume 31, Nº5, September / October 2018

514 Barbosa et al. Primary PCI at night time Int J Cardiovasc Sci. 2018;31(5)513-519 Original Article that hospital admission at night culminates in higher mortality rates, when compared to the daytime period. However, several factors seem to be related to impediments to this access experienced at night, and Brazilian cities have structural problems; plus the fact that emergency care systems usually depend on the on- call Interventional Cardiology professionals, which may prolong the delay until the definitive treatment of STEMI is implemented. 10 Data evaluating the treatment of STEMI in the nighttime period in Brazil are scarce. To date, there have been no outcome-related analyses in Hemodynamic Services with on-duty Interventional Cardiologists. Therefore, the aimof this studywas to evaluate the results of PPCI performed during the daytime and nighttime periods in a cardiology referral center, which has a regular, on-duty interventional cardiologist, together with a specialized nursing team. Methods A prospective observational, single-center cohort study was developed, which included patients with a diagnosis of STEMI of any wall submitted to PPCI within the first 12 hours of the clinical presentation in a tertiary cardiology institution in the municipality of Vitória, state of Espírito Santo, Brazil, between December 2013 and December 2016. The inclusion criteria were the clinical and electrocardiographic diagnoses of IAMCSST, and the indication for treatment byPCI by the attendingphysician, corroborated by the interventional cardiologist. Exclusion criteria were IAMCSST with more than 12 hours of evolution, diagnosis of nonconfirmed or doubtful IAMCSST, patients not submitted to PCII immediately after coronary angiography, The inclusion criteria were the clinical and electrocardiographic diagnoses of STEMI, and the indication of PPCI treatment by the attending physician, corroborated by the interventional cardiologist. The exclusion criteria were STEMI with more than 12 hours of evolution, nonconfirmed or uncertain diagnosis of STEMI, patients not submitted to PPCI immediately after the coronary angiography, patients younger than 18 years of age or refusal to sign the Free and Informed Consent Form (FICF) or to participate in the study through prospective data collection. All patients were interviewed at hospital admission and followed until hospital discharge. The study was approved by the local Research Ethics Committee, according to the Declaration of Helsinki. The patients included in the study were compared according to theperiodof admissionat theHemodynamics service, regardless of the day of the week, specifically at night time, from 7:00 p.m. to 6:59 a.m.; and daytime, from 7 am to 6:59 p.m. The clinical variables evaluated were age, gender, arterial hypertension, diabetes mellitus, dyslipidemia, smoking status, chronic renal failure, prior PCI, previous myocardial revascularization surgery, disease severity at admission described by the Killip- Kimball classification, use of glycoprotein IIb / IIIa inhibitors during PPCI and treatment delay time (door- to-balloon time and pain-to-balloon time). The primary endpoint of the study consisted in combined Major Adverse Cardiac Events (MACE) - death from any cause in the in-hospital phase, new nonfatal AMI or CVA during hospitalization. The secondary outcomes included all-cause death, CVA and new AMI alone, successful PPCI and hospital length of stay in days. At the analysis of hospitalization time, only those patients who were discharged to their homes were considered, excluding those who died during the hospitalization period. All STEMI cases treated at the referral institution had spontaneous demand or were transferred after initial treatment and recognition of the clinical picture at another institution. The emergency nature of the PPCI procedure was followed in all patients, and they were taken to the interventional laboratory as soon as possible after communicating with the emergency unit team. The service had a regular on-duty interventional cardiologist, including at non-commercial hours, operating 24 hours a day. According to the institution’s STEMI care protocol, patients received a loading dose of 200 to 300 mg of acetylsalicylic acid and 300 to 600mg of clopidogrel or 180 mg of ticagrelor. All patients received full heparinization with unfractionated heparin in the interventional laboratory (70 to 100 U/kg). the patients were taken to undergo the procedure as soon as the interventional laboratory was available after conduct confirmation by the interventional cardiologist. After the PPCI procedure, dual antiplatelet therapy was maintained systematically in all patients. The total time of myocardial ischemia in STEMI until the PPCI was performed (pain-to-balloon time) was