PubMed Health⌕ Search

Biomedical subjects

Stuart J Connolly

Publications and source records attributed to Stuart J Connolly.

46 records · Page 3Linked to original sources
PubMed2003

Left Atrial Appendage Occlusion Study (LAAOS): a randomized clinical trial of left atrial appendage occlusion during routine coronary artery bypass graft surgery for long-term stroke prevention.

BACKGROUND: Many patients undergoing coronary artery bypass graft (CABG) surgery have risk factors for both atrial fibrillation (AF) and stroke. The left atrial appendage (LAA) is a main source of thrombus coming from the left atrium. LAA occlusion should be tested as a means to reduce future cerebral ischemic events in these patients. METHODS: The Left Atrial Appendage Occlusion Study (LAAOS) is a randomized clinical trial designed to evaluate the feasibility, safety, and efficacy of LAA occlusion for prevention of ischemic stroke in patients undergoing CABG. The target population consists of patients at risk of AF and stroke who are having routine CABG surgery. The main study will be a prospective, controlled, unblinded trial. Patients at risk of future development of AF, or having AF, will be randomly assigned to undergo or not undergo LAA occlusion. A total of 2500 patients will be randomly assigned and followed for 5 years for the primary outcome of stroke. This study of 2500 patients will have 90% power to detect a relative reduction of 20% in stroke, from a 5-year incidence of 20% in the control group to 16% in the intervention group. Currently, a pilot trial is underway that will enroll 100 patients to assess feasibility, safety, and rates of successful LAA occlusion as assessed by postoperative transesophageal echocardiography. The most suitable surgical technique will also be assessed during the pilot trial. In the pilot study, the main outcomes are safety and rate of successful obliteration of the LAA after surgical occlusion. CONCLUSIONS: The clinical trial designed to evaluate LAA occlusion at the time of routine CABG surgery is currently in the pilot phase.

Aged↗
PubMed2003

Preventing stroke in patients with atrial fibrillation: current treatments and new concepts.

Atrial fibrillation (AF) is common, and it increases the risk of stroke. Placebo-controlled trials consistently showed that warfarin reduces the risk of stroke by two thirds, and a meta-analysis of trials of aspirin show a one-fifth reduction. Meta-analysis of trials directly comparing warfarin and aspirin shows that warfarin reduces the risk of stroke compared with aspirin by about one third. Major advisory bodies recommend risk stratification of patients with AF and prophylactic therapy with warfarin for patients at higher risk. There are several problems with warfarin therapy, which have resulted in a widely documented underuse. These problems include a narrow therapeutic window, marked variability in pharmacokinetics, and contraindications. There are new promising approaches to stroke prevention in AF. One of these is combination antiplatelet therapy. In a large randomized trial, the combination of dipyridamole and aspirin has been shown to have additive benefits against stroke. The combination of clopidogrel and aspirin results in additive benefits against vascular events, with only a modest increase in bleeding. A trial of combined antiplatelet therapy in AF is warranted. Occlusion of the left atrial appendage, either with a transvenous device or with surgery, is another strategy that is being explored. A direct thrombin inhibitor, ximelagatran, has been shown to have an excellent pharmacokinetic profile and is being developed as an oral agent for stroke prevention in AF, and it will not need regular monitoring.

Aspirin↗
PubMed2003

Long-term amiodarone therapy and the risk of complications after cardiac surgery: results from the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial (CAMIAT).

OBJECTIVE: This study was undertaken to determine the association between amiodarone therapy and risk of complications of cardiac surgery in patients in the randomized placebo-controlled, double-blind Canadian Amiodarone Myocardial Infarction Arrhythmia Trial. METHODS: Prospectively collected data regarding postoperative complications in 82 patients who underwent cardiac surgery during Canadian Amiodarone Myocardial Infarction Arrhythmia Trial participation were analyzed; 36 patients were randomly assigned to receive amiodarone and 46 were assigned to receive placebo. Of the patients randomly assigned to receive amiodarone, 24 patients continued amiodarone treatment to within 7 days of the operation (active amiodarone group) and 12 patients had the amiodarone discontinued at least 7 days before the operation (discontinued amiodarone group). RESULTS: The baseline characteristics of the three groups were similar. The risks of ventricular fibrillation, atrial fibrillation, and respiratory complications were similar. The risk of requiring an intra-aortic balloon pump was significantly increased by amiodarone (34.8% vs 16.7% vs 8.7% for active amiodarone, discontinued amiodarone, and placebo groups, respectively, P =.024). There was no significant difference in the use of temporary pacing. Neither the mean duration of stay in the intensive care unit nor the 7- and 30-days mortalities were affected by amiodarone. CONCLUSIONS: Patients receiving long-term amiodarone treatment after myocardial infarction had a higher rate of intra-aortic balloon use after cardiac surgery. There was no increased risk of pulmonary complications, need for pacing, or death.

Administration, Oral↗
PubMed2002

Historical criteria that distinguish syncope from seizures.

OBJECTIVES: We prospectively sought evidence-based criteria that distinguished between seizures and syncope. BACKGROUND: Loss of consciousness is usually due to either seizures or syncope. There are no evidence-based historical diagnostic criteria that distinguish them. METHODS: A total of 671 patients with loss of consciousness completed a 118-item historical questionnaire. Data sets were complete for all subjects. The data set was randomly divided into two equal groups. The contributions of symptoms to diagnoses in one group were estimated with logistic regression and point scores were developed. The accuracy of the decision rule was then assessed using split-half analysis. Analyses were performed with and without inclusion of measures of symptom burden, which were the number of losses of consciousness and the duration of the history. The scores were tested using receiver-operator characteristic analysis. RESULTS: The causes of loss of consciousness were known satisfactorily in 539 patients and included seizures (n = 102; complex partial epilepsy [50 patients] and primary generalized epilepsy [52 patients]) and syncope (n = 437; tilt-positive vasovagal syncope [267 patients], ventricular tachycardia [90 patients] and other diagnoses such as complete heart block and supraventricular tachycardias [80 patients]). The point score based on symptoms alone correctly classified 94% of patients, diagnosing seizures with 94% sensitivity and 94% specificity. Including symptom burden did not significantly improve accuracy, indicating that the symptoms surrounding the loss of consciousness accurately discriminate between seizures and syncope. CONCLUSIONS: A simple point score of historical features distinguishes syncope from seizures with very high sensitivity and specificity.

Case-Control Studies↗
PubMed2002

Interventions on prevention of postoperative atrial fibrillation in patients undergoing heart surgery: a meta-analysis.

BACKGROUND: Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery and has been associated with increased incidence of other complications and increased hospital length of stay (LOS). Prevention of AF is a reasonable clinical goal, and, consequently, many randomized trials have evaluated the effectiveness of pharmacological and nonpharmacological interventions for prevention of AF. To better understand the role of various prophylactic therapies against postoperative AF, a systematic review of evidence from randomized trials was performed. METHODS AND RESULTS: Fifty-two randomized trials (controlled by placebo or routine treatment) of beta-blockers, sotalol, amiodarone, or pacing were identified by systematic literature search. The 3 drug treatments each prevented AF with the following odds ratios (ORs): beta-blockers, 0.39 (95% CI, 0.28 to 0.52); sotalol, 0.35 (95% CI, 0.26 to 0.49); and amiodarone, 0.48 (95% CI, 0.37 to 0.61). Pacing was also effective; for biatrial pacing, the OR was 0.46 (95% CI, 0.30 to 0.71). The influence of pharmacological interventions on LOS was as follows: -0.66 day (95% CI, 2.04 to 0.72) for beta-blockers; -0.40 day (95% CI, 0.87 to 0.08) for sotalol; and -0.91 day (95% CI, 1.59 to -0.23) for amiodarone. The influence for biatrial pacing was -1.54 day (95% CI, -2.85 to -0.24). The incidence of stroke was 1.2% in all the treatment groups combined and 1.4% in controls (OR, 0.90; 95% CI, 0.46 to 1.74). CONCLUSIONS: Beta-blockers, sotalol, and amiodarone all reduce risk of postoperative AF with no marked difference between them. There is evidence that use of these drugs will reduce LOS. Biatrial pacing is a promising new treatment opportunity. There was no evidence that reducing postoperative AF reduces stroke; however, data on stroke are incomplete.

Adrenergic beta-Antagonists↗
PubMed2002

Antiarrhythmic effects of azimilide in paroxysmal supraventricular tachycardia: efficacy and dose-response.

BACKGROUND: Azimilide is a novel classification III antiarrhythmic agent that blocks both I(Kr)and I(Ks)and shows evidence of efficacy in patients with atrial fibrillation or flutter. Its effect on paroxysmal supraventricular tachycardia (PSVT) has not been reported. METHODS AND RESULTS: One hundred ninety-three patients with symptomatic PSVT were enrolled in 4 double-blind, randomized, placebo-controlled clinical trials with almost identical trial design (supraventricular arrhythmia-1 [SVA-1], SVA-2, SVA-3, and SVA-4), performed as a separate stratum of studies that also included a stratum of patients with atrial fibrillation or flutter. Patients received oral azimilide (100 mg in SVA-1 and SVA-3, 35 or 75 mg in SVA-2, and 125 mg in SVA-4) or matching placebo twice daily for 3 days (loading period), followed by once-daily dosing (maintenance period). The primary outcome variable was the first recording of a symptomatic supraventricular arrhythmia (either PSVT, atrial fibrillation, or atrial flutter) recorded on a transtelephonic electrocardiographic event recorder. The duration of study was 270 days in SVA-1 and SVA-2 and 180 days in SVA-3 and SVA-4. Combined analysis results of the PSVT stratum from the 4 studies showed a dose-response relationship in prolongation of time to recurrence (P =.02). In the combined 100-mg daily dose, the hazard ratio (placebo:azimilide) was 2.35 (P =.023). The hazard ratio for the 125-mg daily dose measured 1.28 (P = not significant). However, the time to recurrence was prolonged when the patients receiving 100 and 125 mg daily were combined and compared with placebo (P =.02). There were no deaths and 1 case of torsades de pointes. CONCLUSION: These trial results suggest a significant dose-related suppression of PSVT with azimilide, with a low risk of serious adverse events.

Adult↗
PubMed2002

Quality of life improves with treatment in the Canadian Trial of Atrial Fibrillation.

BACKGROUND: The impact of atrial fibrillation (AF) and its treatment on health-related quality of life (QOL) is not well understood. We assessed QOL in patients with symptomatic AF participating in the Canadian Trial of Atrial Fibrillation. METHODS: Self-report QOL questionnaires including the Short-Form-36 (SF-36), symptom checklist (SCL) and AF Severity Scale (AFSS) were completed at baseline and 3, and 12 months after randomization. RESULTS: The study group was aged 65 +/- 10 years and 59% were male. By design, 50% of patients were randomized to amiodarone (n = 132), 25% to sotalol (n = 66), and 25% to propafenone (n = 66). Most patients had normal left ventricular function (89%). Physical (41.9 +/- 9.3 to 43.7 +/- 9.2, P =.001) and mental health (47.5 +/- 10.5 to 49.0 +/- 9.8, P =.023) summary measures from the SF-36 improved significantly from baseline to 3 months. Arrhythmia symptom frequency and severity (SCL) also improved markedly from baseline to 3 months (symptom frequency 20.4 +/- 9.4 to 16.2 +/- 9.5 and symptom severity 16.7 +/- 8.2 to 12.9 +/- 7.4, both P <.001). QOL improvements were not significantly different among the groups randomized to amiodarone, sotalol, or propafenone. However, patients with no symptomatic recurrences of AF had higher scores at 3 months on measures of global well-being than those with recurrences in the first 3 months (7.4 +/- 1.8 vs 6.9 +/- 1.8, P <.05). There were no significant QOL changes from the 3 to 12 month assessment. CONCLUSION: In patients with symptomatic AF, QOL improves after treatment, independent of the specific drug used for treatment. This is especially true for patients in whom treatment prevents AF recurrence.

Aged↗
PubMed2002

Quality of life in the Canadian Implantable Defibrillator Study (CIDS).

BACKGROUND: The primary aim of this study was to compare quality-of-life outcome between patients randomized to implantable cardioverter defibrillator (ICD) therapy and patients randomized to amiodarone treatment in the Canadian Implantable Defibrillator Study (CIDS). A secondary aim was to evaluate the effects on quality-of-life outcomes of receiving shocks from the device. METHODS: Quality of life was assessed in 317 English-speaking participants by use of the Rand Corporation's 38-item Mental Health Inventory (MHI) and the Nottingham Health Profile (NHP). Assessments were done in the hospital at baseline and with mailed questionnaires after 2, 6, and 12 months of follow-up. Sixty-two percent of patients completed the follow-up assessments at 6 and 12 months. RESULTS: Repeated measures analysis of variance revealed significant time by treatment group interaction effect on total MHI and the psychological distress and psychological well-being sub-scales, and on 5 of the 7 NHP scales (energy, physical mobility, emotional reactions, sleep disturbance, and lifestyle impairment) (P <.05). Emotional and physical health scores were shown to improve significantly in the ICD group and were either unchanged (emotional health) or deteriorated (energy and physical mobility) in the amiodarone-treated group by means of post-hoc comparisons. Quality of life did not improve in the subgroup of patients in the ICD-treated group who received > or =5 shocks from their device. CONCLUSION: Quality of life is better with ICD therapy than with amiodarone therapy. The beneficial quality-of-life effects from an ICD are not evident in patients who receive numerous shocks from their device.

Aged↗
PubMed2002

Effects of azimilide on heart rate and ECG conduction intervals during sinus rhythm in patients with a history of atrial fibrillation.

The purpose of this study was to assess the effect of azimilide, a Class III antiarrhythmic drug, on ECG conduction intervals recorded during sinus rhythm in patients with a history of symptomatic atrial fibrillation or atrial flutter. In Phase I clinical pharmacology studies, azimilide was associated with prolongation of the QT and QTc intervals on electrocardiograms recorded during sinus rhythm in normal subjects, but the effect of azimilide on the target population of patients with atrial fibrillation has not been reported in detail previously. Patients with a history of atrial fibrillation, atrial flutter, or both were randomly assigned to receive placebo or azimilide twice daily for 3 days and then qd thereafter. Azimilide doses of 50 mg, 100 mg, or 125 mg were tested. The RR, PR, QRS, QT, QTc(Bazett), and QTc(Fridericia) intervals were measured from electrocardiograms recorded at baseline and on Day 4 of test therapy. Increasing azimilide doses were associated with significant increases in the RR, QT, QTc(Bazett), and QTc(Fridericia) compared with changes in the placebo group based on the F-test for differences among treatment groups and the test for a dose response. In the azimilide 125 mg dose group, the mean change in RR was significantlygreater than the mean change in the placebo group (+61.4 ms in the azimilide 125 mg group vs. -14.1 ms in the placebo group). The mean change in QT was significantly greater in the azimilide 125 mg group than the mean change in the placebo group (+44.2 ms in the azimilide 125 mg group vs. -1.0 ms in the placebo group). The mean change in QTc using both correction methods was significantly greater in the azimilide 125 mggroup than the mean change in the respective placebo group: QTc(Bazett) +31.6 ms in the azimilide 125 mg group versus +2.1 ms in the placebo group and QTc(Fridericia) +35.8 in the azimilide 125 mg group versus +1.0 ms in the placebo group. It was concluded that in patients with a history of atrial fibrillation or flutter, azimilide was associated with statistically significant increases in RR, QT, QTc(Bazett), and QTc(Fridericia) when patients were in sinus rhythm.

Analysis of Variance↗