Cost effectiveness of cardiac resynchronization therapy in the Nordic region: an analysis based on the CARE-HF trial.

BACKGROUND: The aim of this study was to investigate the cost-effectiveness of cardiac resynchronization therapy (CRT) in Denmark, Finland and Sweden. The analysis was based on the CARE-HF trial, a randomised clinical trial investigating the efficacy of adding CRT (n=409) to optimal pharmacological treatment (n=404) in patients with moderate to severe heart failure with markers of cardiac dyssynchrony. The average follow-up time was 29.4 months. METHODS: The health effects were measured in terms of quality-adjusted life years (QALYs) gained. Data on health care resource consumption from CARE-HF was combined with costs for CRT implantation and hospitalisation from university hospitals in Denmark, Finland and Sweden. Calculations were based on patients' expected life time. The expected device lifetime (6 years) was used for CRT, and no additional gains in clinical effects were assumed after the 6 years. RESULTS: The cost-effectiveness ratio per QALY gained was 4800 euros in Denmark, 3600 euros in Finland and 6700 euros in Sweden. The 95% confidence intervals for the cost per QALY gained varied between a lower limit of 1169 euros in Finland to an upper limit of 17,482 euros in Sweden. These values were all below the threshold for being cost-effective in Denmark, Finland and Sweden. CONCLUSIONS: The study indicates that CRT is a cost-effective treatment in Scandinavian health care settings compared to traditional pharmacological therapy and can therefore be recommended for routine use in patients with moderate to severe heart failure and markers of dyssynchrony.

Effects of the maze operation on health-related quality of life in patients with atrial fibrillation.

BACKGROUND: Maze surgery for atrial fibrillation (AF) is a curative therapy, but its effect on health-related quality of life has not been studied. METHODS AND RESULTS: Maze operations were performed in 48 patients with drug-refractory AF. The majority of patients (80%) had lone AF, and the primary indication for surgery in all patients was AF. The SF-36 Health Survey was used to assess quality of life before operation and at 6 months and 1 year after surgery. Twenty-five patients were available for the 1-year follow-up and completed all questionnaires. Before maze surgery, the SF-36 scores were significantly lower than in the general Swedish population, reflecting significant impairment in well-being, physical and social functioning, and mental health. After maze surgery, the quality of life was significantly improved at 6 months and at 1 year on all scales except for bodily pain, which, however, was not significantly decreased before surgery. At both 6 months and 1 year after maze surgery, quality of life, measured by the SF-36, reached the levels of the general Swedish population. CONCLUSIONS: The maze operation can significantly improve the health-related quality of life in selected groups of patients with both paroxysmal and chronic AF refractory to antiarrhythmic therapy.

Tachyarrhythmias and triggering factors for atrial fibrillation after coronary artery bypass operations.

BACKGROUND: We evaluated the role of supraventricular arrhythmias and assessed clinical predictors of atrial fibrillation (AF) that developed after coronary artery bypass operations. METHODS: Eighty patients, with a mean age of 65.8 years, underwent 24-hour Holter monitoring preoperatively and for 4 consecutive days postoperatively, or until clinically documented AF, for analysis of the number of premature beats and tachyarrhythmias. Atrial areas and atrial peptides were measured preoperatively and postoperatively. RESULTS: Twenty-nine of 80 (36.3%) patients had postoperative AF. Preoperatively, the maximal supraventricular premature beats per minute were higher in the AF group (p = 0.02). The body mass index and total amount of cardioplegia were lower (p = 0.02 and p = 0.006, respectively), and withdrawal of beta-blockers postoperatively more frequent (p = 0.001) in the AF group, but atrial areas and atrial peptides did not differ. CONCLUSIONS: Frequent supraventricular premature beats preoperatively may indicate a propensity for AF. A larger amount of cardioplegia during the cross-clamp period may reduce the risk of postoperative AF. Further studies are mandatory to clarify why patients with lower body mass index were more prone to AF.

Thoracic epidural anesthesia does not influence the occurrence of postoperative sustained atrial fibrillation.

BACKGROUND: To evaluate whether thoracic epidural anesthesia (TEA) can reduce the incidence of atrial fibrillation (AF) after coronary artery bypass grafting (CABG). METHODS: Forty-one patients undergoing CABG were treated with TEA intraoperatively and postoperatively. Another 80 patients served as the control group. The sympathetic and parasympathetic activities were evaluated by analysis of neuropeptides, catecholamines and heart rate variability (HRV), preoperatively and postoperatively. RESULTS: Postoperative AF occurred in 31.7% of the TEA-treated patients and in 36.3% of the untreated patients (p = 0.77). TEA significantly suppressed sympathetic activity, as indicated by a less pronounced increase of norepinephrine and epinephrine (p = 0.03, p = 0.02) and a significant decrease of neuropeptide Y (p = 0.01) postoperatively in TEA-treated patients compared to untreated patients. The HRV variable expressing sympathetic activity was significantly lower and the postoperative increase in heart rate was significantly less in the TEA group than in the control group after surgery (p = 0.01, p < 0.001). Among patients developing AF, the maximal number of supraventricular premature beats per minute increased significantly in untreated patients postoperatively but remained unchanged in TEA-treated patients (p = 0.004 versus p = 0.86). CONCLUSIONS: TEA has no effect on the incidence of postoperative sustained AF, despite a significant reduction in sympathetic activity.

The sensitivity of transesophageal pacing for screening in atrial tachycardias.

Transesophageal atrial pacing and recording performed in 128 patients for palpitations or tachycardia was retrospectively evaluated and compared to the same procedure in 77 routinely evaluated patients after a catheter ablation procedure. The sensitivity and specificity of the described protocol was 74 and 90% respectively. The procedure was well tolerated and a majority of patients could be completely evaluated according to the protocol. The outcome of the first time investigation influenced the subsequent choice of therapy in the studied population. The results suggest that transesophageal pacing is a valuable tool for evaluation of atrial tachycardias with specificity, sensitivity and tolerability comparable to other noninvasive methods used in cardiology.

The relationship between intraoperatively assessed atrial and ventricular insertions of accessory pathways.

To gain insight into the complex problems regarding the extension of the atrial and ventricular insertions of anomalous pathways, the activation patterns obtained from intraoperative epicardial mapping in 23 patients with Wolff-Parkinson-White syndrome were carefully analyzed. The atrial and ventricular activation times along the atrioventricular groove were measured at 15 predefined anatomical landmarks. The width of the region of earliest atrial and ventricular activation times and the extent of atrial and ventricular overlap were assessed. The relationship between the atrial and ventricular insertions was studied by predicting the ventricular insertions from the observed atrial insertions and vice versa. The mean extension of an atrial and a ventricular insertion at surgery was 1.9 +/- 0.2 (SE) and 1.6 +/- 0.2 (SE) anatomical landmarks, respectively. The width of the region of early atrial and ventricular activation times measured 2.7 +/- 0.3 (SE) landmarks, thus indicating an overlap of the atrial and ventricular insertions. The lateral distance between the sites of earliest atrial and ventricular activation times was, on average, 1.7 +/- 0.3 (SE) landmarks. The predicted atrial insertion from a known ventricular insertion, and vice versa was found to cover 4 to 6 anatomical landmarks. These observations suggest that wide surgical dissections along the atrioventricular groove are warranted even if epicardial mapping discloses only a single accessory pathway.

Clinical value of transesophageal atrial stimulation and recording in patients with arrhythmia-related symptoms or documented supraventricular tachycardia--correlation to clinical history and invasive studies.

The main objective of the present study was to evaluate the clinical applicability of transesophageal atrial stimulation (TAS) and recording with regard to inducibility of supraventricular tachycardia (SVT) in patients with either an ECG-documented paroxysmal SVT or a clinical history of palpitations suggesting this disease. A further objective was to assess the inducibility of SVT and to compare the inducibility by TAS with that obtained by an invasive electrophysiologic study (EPS). A total of 64 patients (aged 13-74 years) with ECG-documented paroxysmal SVT (n = 50) or only a history of palpitations (n = 14) was referred for TAS. Preexcitation was present in 35 patients. The study protocol included single and double extrastimuli delivered at a basic paced interval of 500 ms, and incremental atrial stimulation until a cycle length of 275 ms or a second-degree AV block appeared. In 10 patients atropine intravenously was required for induction. The same protocol was used in 34 of the patients who also underwent invasive EPS. TAS was completed in 56 of 64 patients (88%). In this group SVT was induced during TAS in 84% (47/56). Of patients with ECG-documented tachycardia, clinical tachycardia was induced in 90% (35/39) with ECG-documented regular paroxysmal SVT and in 67% of patients (4/6) with ECG-documented atrial fibrillation. In patients without ECG-documented atrial fibrillation. In patients without ECG-documented tachycardia, clinically relevant arrhythmia was induced in 73% (8/11). In 30 of 32 patients (94%) with an inducible tachycardia during invasive EPS, it was also possible to induce the tachycardia by TAS.(ABSTRACT TRUNCATED AT 250 WORDS)

[The diagnostic value of esophageal ECG and transesophageal atrial stimulation in paroxysmal supraventricular tachycardia]. / Den diagnostiske vaerdi af esophagus-ekg og transøsofageal atrial stimulation ved paroksystisk supraventrikulaer takykardi.

Paroxysmal supraventricular tachycardia (PSVT) includes a group of common arrhythmias. The diagnosis should be based on 12-lead ECG. Oesophageal ECG, which registers mainly left-sided posterior atrial activity may be of value for further assessment of the arrhythmic mechanism in determination of the time relationship between atrial and ventricular signals. A ventriculoatrial interval during PSVT measured by oesophageal ECG of under 70 ms is evidence of atrioventricular nodal re-entry tachycardia while an interval of over 70 ms suggests orthodromic reciprocating tachycardia with participation of an accessory atrioventricular pathway. Transoesophageal atrial stimulation (TAS) via an electrode catheter is possible in approximately 90% of the patients with PSVT. TAS requires greater quantities of energy than endocardial stimulation and is associated with slight to moderate retrosternal discomfort. The method renders possible both programmed stimulation with the object of inducing arrhythmia and in stopping the majority of cases PSVT, with the exception of atrial fibrillation. The method is relatively simple, non-invasive, requires few resources and can be carried out on outpatients.

Epiglottitis and torsade de pointes tachycardia.

Severe throat infection is not usually associated with a higher risk of paroxysmal attacks of torsade de pointes tachycardia. A patient is reported in whom epiglottitis was associated with the sudden development of cardiac syncope caused by an acquired adrenergic-dependent long QT syndrome and the development of ventricular arrhythmias.

Amiodarone in atrial fibrillation.

Twenty-seven patients with atrial fibrillation without any concomitant conduction abnormality have been treated with oral amiodarone in a daily maintenance dose of 200 mg. The drug has been used for three purposes: 1) to block atrioventricular conduction, thereby decreasing the ventricular rate during atrial fibrillation (9 patients), 2) as prophylaxis against paroxysmal atrial fibrillation (8 patients), 3) as prophylaxis against recurrence of atrial fibrillation after DC conversion to sinus rhythm (13 patients). All patients were considered refractory to other antiarrhythmic drugs in these respects. In the second group, 4 of the 8 patients reported complete cessation of attacks and the others a marked reduction of the attack rate. In the third group, 10 of the 13 patients have maintained sinus rhythm for a longer period on treatment with amiodarone than with other drugs, resulting more than a triple prolongation of the time in sinus rhythm. In 3 patients the drug has been discontinued because of side-effects. In conclusion, amiodarone affords protection from episodes of paroxysmal atrial fibrillation, as well as from recurrence of atrial fibrillation after DC conversion to sinus rhythm. If the drug is ineffective in either of these respects, it may still be useful as a means of moderating the ventricular response in atrial fibrillation.

Identification of multiple pathways in the Wolff-Parkinson-White syndrome. Diagnostic problems and therapeutic implications.

With advanced electrophysiological methods evaluation of functional properties and location of accessory pathways has become possible. Multiple pathways may, however, be difficult to outline with regard to localization and electrophysiological properties due to differences in refractoriness and/or fusion of conduction between the pathways. The investigational procedures in patients with multiple accessory pathways are described and discussed in connection with an illustrative patient with three accessory pathways, two of which are Kent's bundles and one most probably a Mahaim's bundle.