Cheryl Sirois

Atrial fibrillation after minimally invasive coronary artery bypass grafting: A retrospective, matched study

BACKGROUND Atrial fibrillation after cardiac operations is a source of morbidity and resource consumption. Various factors common to cardiac operations have been cited as causal. Comparison of the incidences of atrial fibrillation after conventional cardiac operations and minimally invasive cardiac operations may provide some insight into the mechanisms of this complication. METHODS All patients undergoing minimally invasive direct coronary artery bypass grafting from January 26, 1996, through September 17, 1997, were evaluated for the occurrence of in-hospital postoperative atrial fibrillation. Data from these 55 patients were compared with data from a control cohort of patients undergoing conventional, solitary coronary artery bypass grafting. Each patient undergoing minimally invasive direct coronary artery bypass grafting was matched by age (+/- 3 years) and date of operation (+/- 7 days) with a patient undergoing conventional coronary artery bypass grafting. RESULTS During the period since the advent of minimally invasive direct coronary artery bypass grafting at our institution, the incidence of postoperative atrial fibrillation has been slightly lower among the patients undergoing this form of coronary artery bypass grafting (26%) than among the total population of patients undergoing conventional coronary artery bypass grafting (34%). Comparison of the age-matched groups, however, showed the incidence to be slightly but not significantly greater in the minimally invasive direct coronary artery bypass grafting cohort (13/55, 24%) than in the conventional coronary artery bypass grafting cohort (11/55, 20%; P =. 6). The minimally invasive direct coronary artery bypass grafting group was less likely to be discharged with antiarrhythmic therapy than was the conventional coronary artery bypass grafting group (6 versus 10; P =.006). CONCLUSIONS According to these data, mechanisms traditionally implicated in atrial fibrillation after coronary artery bypass grafting, such as the use of cardiopulmonary bypass, mechanical manipulation of the atrium, and atrial ischemia, are not causal but may be related to the duration of the arrhythmic complication. Strategies directed toward management and reduction of the incidence of postoperative atrial fibrillation should be focused accordingly.

The prediction of cardiac surgery outcome based upon preoperative psychological factors

Abstract The present study was designed to investigate whether preoperative anxiety and anger were predictive of postoperative outcome in cardiac surgery parients. A standardized scale measuring state and trait anxiety and anger was completed by 94 patients awaiting cardiac surgery. Dependent measures included length of stay, number of complications, and clinical rating of surgical outcome. Higher levels of preoperative state anxiety and anger were associated with poorer postoperative outcome. These results were obtained after adjusting for medical status, surgical procedure, preoperative length of stay, priority of surgery, gender, and age. These relationships suggest a potential role for interventions aimed at altering presurgical psychological states.

Cutaneous closure after cardiac operations : A controlled, randomized, prospective comparison of intradermal versus staple closures

OBJECTIVE To determine the difference in wound complication and infection rates between suture and staple closure techniques applied to clean incisions in coronary bypass patients. BACKGROUND The true incidence of postoperative wound complications, and their correlation with closure techniques, has been obscured by study designs incorporating small numbers, retrospective short follow-up, uncontrolled host factors, and narrowly defined complications. METHODS Sternal and leg wounds were studied prospectively, each patient serving as his or her own control. Two hundred forty-two patients with sternal and saphenous vein harvest wounds had half of each wound closed with staples and the other half with intradermal sutures (484 sternal and 516 leg segments). Wound complications were defined as drainage, erythema, separation, necrosis, seroma, or infection. Infections were identified in the subset having purulent drainage, antibiotic therapy, or debridement. Wounds were examined at discharge, at 1 week after discharge, and at 3 to 4 weeks after operation. Patient preferences for closure type were assessed 3 to 4 weeks after operation. RESULTS Neither leg nor sternal wounds had a statistically significant difference in infection rate according to closure method (leg sutured = 9.3% vs. leg stapled = 8.9%; p = 0.99, and sternal sutured = 0.4% vs. sternal stapled = 2.5%; p = 0.128). There was, however, a greater complication rate in stapled segments (leg stapled = 46.9% vs. leg sutured = 32.6%; p = 0.001, and sternal stapled = 14.9% vs. sternal sutured = 3.7%; p = 0.00005). Sutures were favored over staples among patients who expressed a preference (sternal = 75.6%, leg = 74.6%). CONCLUSIONS With the host factors controlled by pairing staples and sutures in each patient, we demonstrated a similar incidence of infection but a significantly lower incidence of total wound complications with intradermal suture closure than with staple closure.

CABG after successful PTCA: A case-control study

We sought characteristics predictive of the need for operative revascularization subsequent to a successful coronary angioplasty. Through June 1993, 128 patients who had successful percutaneous transluminal coronary angioplasty (PTCA) between January 1982 and March 1989 required subsequent coronary artery bypass grafting (CABG) at our hospital. These cases were matched with 128 controls who had a successful PTCA but did not require subsequent CABG. Controls were matched to cases by the date of their initial PTCA. Before initial PTCA there were no differences between the cases and controls in terms of age, sex, prior myocardial infarction, ejection fraction, duration of anginal symptoms, hypertension, hyperlipidemia, family history, or obesity (all not significant). A greater number of cases had diabetes (35 versus 18; p = 0.009). Angiography before initial PTCA revealed that cases had a greater mean number of total lesions (4.1 versus 3.3; p = 0.002) and a higher incidence of left anterior descending and circumflex artery stenoses of 70% or greater (98 versus 75 and 57 versus 34, respectively; p = 0.006). The mean number of lesions successfully dilated was greater in cases (2.4 versus 1.7; p = 0.0001). Cases had CABG at a mean interval of 16.7 +/- 23 months. There were 17 late deaths among cases and 9 among the controls at a mean of 38.6 +/- 30 months. The survival probability at 5 years was 94.5% for controls and 87.9% for cases (p = 0.048). Initial revascularization by PTCA is followed by CABG at a brief interval in a subset of patients who have markers of more severe disease than do patients who do not require early CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Potassium concentrations and ventricular ectopy: a prospective, observational study in post-cardiac surgery patients.

OBJECTIVE To determine whether a correlation exists between concentrations of intracellular and extracellular potassium and to determine the frequency of ventricular ectopy in patients after cardiac operations. DESIGN Prospective, observational clinical evaluation. SETTING Surgical-respiratory intensive care unit of a university-affiliated tertiary care center. PATIENTS Continuous 24-hr electrocardiographic monitoring was performed, and serum (extracellular) and erythrocyte (intracellular) potassium concentrations ([K+]e and [K+]i) were determined, before cardiopulmonary bypass, immediately postoperatively, and at 2, 4, 12, and 20 hrs after elective coronary bypass grafting in 31 patients. INTERVENTIONS None. Potassium replacement was left to the discretion of the attending physicians. MEASUREMENTS AND MAIN RESULTS Although the mean [K+]e varied significantly during the postoperative 24-hr period (p<.0001), the [K+]i did not (p = .953). No significant correlations were found between premature ventricular beats and [K+]i, [K+]e, or [K+]i/[K+]e (all p>.05). However, among the few patients who had one or more episodes of ventricular tachycardia (VT) within 30 mins of a study K+ sample, the mean [K+]e was significantly lower during the episode(s) of VT compared with the mean [K+]e in the absence of VT (p<.01). CONCLUSIONS Although it is clear that over the clinically acceptable range of [K+]e and [K+]i concentrations seen in this population, there is no correlation between potassium concentrations and the occurrence of premature ventricular beats, the infrequent association of more serious ventricular ectopy, VT, with lower [K+]e concentrations supports the practice of using serum potassium to guide potassium replacement in patients after cardiac operations.