Risk Factors of Atrial Fibrillation After Cardiac Surgery

Overview

Supraventricular arrhythmias complicate more than 40% of cardiac surgeries and are associated with an increased risk of bleeding, stroke, heart failure, and death. Preventing the occurrence of these arrhythmias is a major challenge. This study aims to investigate risk factors and protective factors regarding atrial fibrillation and other iatrogenic cardiac arrhythmias after cardiac surgery, particularly innovative anesthetic strategies such as stellar ganglion blockade which have been recently implemented in our center.

STUDY OBJECTIVE The aim of this study is to compare atrial fibrillation incidence between patients having undergone a cardiac surgery with a stellate ganglion block and patients having undergone a cardiac surgery without a stellate ganglion block . STUDY PROCEDURES This study does not require any additional examinations or specific treatments. It uses information already routinely available in the CHR Mercy electronic medical record systems (Diane, Metavision, dxCare). This is a prospective single-center study. Patients referred for cardiac surgery (both off-pump and on-pump procedures) will be included for data collection between June 2026 and June 2029. The use of a stellate ganglion block after a cardiac surgery is a routine practice in our hospital that varies depending on the intensivist and/or the time period. Clinical, demographic, and biological data will be collected in patient records. Perioperative data related to the surgical procedure will also be collected, as well as data regarding the management and clinical course during the intensive care unit stay. The socio-demographic data collected as part of routine clinical care will include: age, sex, past medical and surgical history, chronic medications, type of cardiac disease, coronary angiography findings, history of coronary stenting, stent localization, preoperative assessment (lower limb Doppler ultrasound, carotid Doppler ultrasound), type of coronary artery bypass surgery (off-pump/on-pump), and history of cardiac arrhythmias. The following clinical data, routinely collected on a daily basis as part of standard care, will be recorded: blood pressure, heart rate, body temperature, respiratory rate, duration of mechanical ventilation, daily urine output (mL), FiO2 (for intubated patients, otherwise oxygen flow rate), need for non-invasive ventilation (Yes/No) assessed daily, mobilization to chair (Yes/No), presence of clinical Claude Bernard-Horner syndrome, recurrent laryngeal nerve palsy, swallowing disorders/aspiration events, inflammatory signs around the perineural catheter, pain at the puncture site/cervical region, chest pain assessed using a visual analogue scale (VAS), signs of phrenic nerve paralysis (reduced thoracic expansion on the stellate block side), acute neurological disorders (confusion, agitation, seizures), daily chest drain output, number and location of chest drains, type and dosage of inotropic support (dobutamine, levosimendan), type and dosage of vasopressors (norepinephrine, vasopressin). The following paraclinical data will be monitored daily: ECG recordings (D1, D2, D3, D4), continuous ECG Holter monitoring, chest X-ray on D0 as part of routine care, and transthoracic echocardiography (TTE) performed routinely on D1, D2, D3, and D4, including: left ventricular outflow tract velocity-time integral (LVOT VTI), heart rate, LVOT area (cardiac output/cardiac index calculation), E-wave velocity (cm/s), A-wave velocity (cm/s), mitral E' velocity (cm/s), TAPSE (mm), tricuspid S-wave velocity (cm/s), pericardial effusion (Yes/No), inferior vena cava diameter (mm), aortic regurgitation grade (1-4), mitral regurgitation grade (1-4), maximum intraventricular gradient (mmHg), and mean transvalvular gradient (mmHg). Biological data collected as part of routine care Day 0 (D0) Serum electrolytes (sodium, potassium), renal function tests (serum creatinine, urea), liver function tests (AST, ALT, gamma-GT, alkaline phosphatase, total bilirubin, conjugated bilirubin), troponin, NT-proBNP, CPK, complete blood count, PT, aPTT, fibrinogen, and serum bicarbonate levels. Day 1 (D1) (and all consecutive days in ICU) Serum electrolytes (sodium, potassium), renal function tests (serum creatinine, urea), liver function tests (AST, ALT, gamma-GT, alkaline phosphatase, total bilirubin, conjugated bilirubin), troponin, NT-proBNP, CPK, complete blood count, PT, aPTT, fibrinogen, serum bicarbonates, plus venous blood gas analysis (pH, lactate, PaO2, PaCO2, bicarbonates, ScvO2) and arterial blood gas analysis (pH, lactate, PaO2, PaCO2, bicarbonates, SaO2, PaO2/FiO2 ratio). Those biological data will be monitored as long as the patient is in ICU.