Determinants of label non-adherence to non-vitamin K oral anticoagulants in patients with newly diagnosed atrial fibrillation

Aims

To evaluate the extent and determinants of off-label non-vitamin K oral anticoagulant (NOAC) dosing in newly diagnosed Dutch AF patients.

Methods and results

In the DUTCH-AF registry, patients with newly diagnosed AF (<6 months) are prospectively enrolled. Label adherence to NOAC dosing was assessed using the European Medicines Agency labelling. Factors associated with off-label dosing were explored by multivariable logistic regression analyses. From July 2018 to November 2020, 4500 patients were registered. The mean age was 69.6 ± 10.5 years, and 41.5% were female. Of the 3252 patients in which NOAC label adherence could be assessed, underdosing and overdosing were observed in 4.2% and 2.4%, respectively. In 2916 (89.7%) patients with a full-dose NOAC recommendation, 4.6% were underdosed, with a similar distribution between NOACs. Independent determinants (with 95% confidence interval) were higher age [odds ratio (OR): 1.01 per year, 1.01–1.02], lower renal function (OR: 0.96 per ml/min/1.73 m2, 0.92–0.98), lower weight (OR: 0.98 per kg, 0.97–1.00), active malignancy (OR: 2.46, 1.19–5.09), anaemia (OR: 1.73, 1.08–2.76), and concomitant use of antiplatelets (OR: 4.93, 2.57–9.46). In the 336 (10.3%) patients with a reduced dose NOAC recommendation, 22.9% were overdosed, most often with rivaroxaban. Independent determinants were lower age (OR: 0.92 per year, 0.88–0.96) and lower renal function (OR: 0.98 per ml/min/1.73 m2, 0.96–1.00).

Conclusion

In newly diagnosed Dutch AF patients, off-label dosing of NOACs was seen in only 6.6% of patients, most often underdosing. In this study, determinants of off-label dosing were age, renal function, weight, anaemia, active malignancy, and concomitant use of antiplatelets.

Pleomorphic ventricular tachycardia in dilated cardiomyopathy is a strong predictor of VT recurrence after ablation independent of cardiac function: Comparison with ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

 

Compared to ICM patients, subgroups of DCM patients show higher VT recurrence rates after catheter ablation (CA), despite similar percentages of acute non-inducibility. Pleomorphic VTs (PL-VT) have been reported in ICM patients with fibrotic remodeling and progressive heart failure.  Diffuse fibrosis is the dominant scar pattern in DCM. In these patients PL-VT may occur independent of cardiac function. 

Aim

 

To investigate the prevalence, relation with cardiac function, and impact of PL-VT on long-term ablation outcome in patients with ICM and DCM. 

Methods

 

Consecutive patients with ICM or DCM undergoing VT ablation (ICM 2009-2016; DCM 2008-2018) were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT morphology lasting for ≥6 consecutive beats during the same induced VT episode. Complete procedural success was defined as non-inducibility of any VT at the end of the procedure. Patients were followed for VT recurrence and mortality. 

Results

 

A total of 247 patients (86% men, age 63 ± 13 years) underwent CA for monomorphic VT, 152 with ICM (62%), and 95 with DCM (38%). Complete procedural success was achieved in 39% in ICM vs. 37% in DCM, respectively. PL-VT was observed in 22 and 29 patients with ICM and DCM, respectively (14% vs. 31%, P = 0.003). Among ICM patients, PL-VT was associated with a lower LVEF (PL-VT+ 28 ± 9% vs. PL-VT- 34 ± 12%, P = 0.02) and only occurred if LVEF was <40%. In contrast, in DCM patients, PL-VT was not related to cardiac function and occurred in 27% of patients with an EF >40%. After propensity score matching to account for baseline differences (age, gender, LVEF, prior VT ablation, VT storm, and amiodarone use), between ICM vs. DCM patients, the PLVT incidence was 4 times higher in DCM patients (7% [4/60] vs. 28% [17/60], P = 0.003).  

During a median follow-up of 30 months, 79 (32%) patients died (ICM 48 [32%), DCM 31 [33%], P = 0.88) and 120 (49%) patients had VT recurrence (ICM 59 [39%], DCM 61 [64%], P < 0.001). In Kaplan-Meier analyses, inducibility of PL-VT was associated with mortality only in ICM but not in DCM patients. In contrast, PL-VT was associated with poorer VT-free survival in both ICM and DCM patients (figure). In multivariate analyses, PL-VT remained a significant predictor of VT recurrence in DCM (HR 3.00, 95% CI 1.75-5.11, P < 0.001), independent of LVEF, (likely) pathogenic genetic mutation, amiodarone, endocardial low bipolar/unipolar voltage areas, dominant anteroseptal substrate, and non-complete acute procedural success, but not in ICM.

Conclusions

 

PL-VT was associated with poor systolic function and mortality in ICM, whereas it was independent of LVEF and the most decisive parameter for VT recurrence in DCM. This data suggests that PL-VT in DCM is a marker of a complex arrhythmic substrate challenging to control by CA. Abstract Figure. Kaplan-Meier analyses

Outcome of stand-alone thoracoscopic epicardial left atrial posterior box isolation with bipolar radiofrequency energy for longstanding persistent atrial fibrillation

Introduction

Catheter ablation of longstanding (> 1 year) persistent atrial fibrillation (AF) is associated with poor outcome. This might be due to remodelling and fibrosis formation, mainly located in the posterior left atrial (LA) wall. Therefore, we adopted a thoracoscopic epicardial box isolation of the posterior left atrium using bipolar RF energy with intraoperative testing of conduction block.

Methods and results

Bilateral thoracoscopic box isolation was performed with a bipolar RF clamp. Entrance block was defined as absence of a conducted electrogram within the box, while exit block was confirmed by pacing at 10.0 V/2 ms. Ablation outcome was evaluated after 3, 6, 12 and 24 months with 12-lead ECGs and 24-hour Holter recordings.

Twenty-five consecutive patients were included (58 ± 7 years, persistent AF duration 1.8 ± 0.9 years). Entrance block was achieved in all patients and exit block confirmed if sinus rhythm was achieved. After 17 ± 7 months, 76 % of the patients (n = 19) were free of AF recurrence. One patient died within 1 month and was considered an ablation failure. Four patients with AF recurrences regained sinus rhythm with additional catheter ablation or antiarrhythmic drugs.

Conclusions

Treatment of longstanding persistent AF with thoracoscopic epicardial LA posterior box isolation using bipolar RF energy with intraoperative testing of conduction block is feasible and highly effective.

Risk factors and time delay associated with cardiac device infections: Leiden device registry

AIMS

A nested case-control study of 75 patients with cardiac device infections (CDI) and 75 matched controls was conducted to evaluate time course, risk factors, culture results and frequency of CDI.

METHODS AND RESULTS

CDI occurred in 75/3410 (2.2%) device implantation and revision procedures, performed between 2000 and 2007. The time delay between device procedure and infection ranged from 0 to 64 months (mean 14 (SD 16)), 21 patients (28%) had an early infection (<1 month), 26 (35%) a late infection (1-12 months) and 28 (37%) a delayed infection (>12 months). Of interest, 18 (24%) patients presented with an infection >24 months after the device-related procedure. Time delay until infection was significantly shorter when cultures were positive for micro-organisms compared to negative cultures (8 (12) vs 18 (18) months, p = 0.03). Pocket cultures in delayed infections remained more often negative (61% vs 23%, p = 0.01). Independent CDI risk factors were: device revision (odds ratio (OR) 3.67; 95% confidence interval (CI), 1.51 to 8.96), renal dysfunction defined as glomerular filtration rate <60 ml/min (OR 4.64; CI, 1.48 to 14.62) and oral anticoagulation use (OR 2.83; CI 1.20 to 6.68).

CONCLUSION

CDI occurred in 2.2% of device procedures, with 24% occurring more than two years after the device-related procedure. Renal dysfunction, device revisions and oral anticoagulation are potent risk factors for CDI.

Oxygen wastage of stunned myocardium in vivo is due to an increased oxygen cost of contractility and a decreased myofibrillar efficiency

OBJECTIVE

We investigated whether an increased oxygen cost of contractility and/or a decreased myofibrillar efficiency contribute to oxygen wastage of stunned myocardium. Because Ca(2+)-sensitizers may increase myofibrillar Ca(2+)-sensitivity without increasing cross-bridge cycling, we also investigated whether EMD 60263 restores myofibrillar efficiency and/or the oxygen cost of contractility.

METHODS

Regional fiber stress and strain were calculated from mesomyocardially implanted ultrasound crystals and left ventricular pressure in anesthetized pigs (n=18). Regional myocardial oxygen consumption (MVO(2)) was measured before contractility (end-systolic elastance, E(es)) and total myofibrillar work (stress-strain area, SSA) were determined from stress-strain relationships. Atrial pacing at three heart rates and two doses of dobutamine were used to vary SSA and E(es), respectively. After stunning (two times 10-min ischemia followed by 30-min reperfusion), measurements were repeated following infusion of saline (n=8) or EMD 60263 (1.5 mg.kg(-1) i.v., n=10). Linear regression was performed using: MVO(2)=alpha.SSA+beta.E(es)+gamma.HR(-1) (alpha(-1), myofibrillar efficiency; beta, oxygen cost of contractility; and gamma, basal metabolism/min).

RESULTS

Stunning decreased SSA by 57% and E(es) by 64%, without affecting MVO(2), while increasing alpha by 71% and beta by 134%, without affecting gamma. From the wasted oxygen, 72% was used for myofibrillar work and 18% for excitation-contraction coupling. EMD 60263 restored both alpha and beta.

CONCLUSIONS

Oxygen wastage in stunning is predominantly caused by a decreased myofibrillar efficiency and to a lesser extent by an increased oxygen cost of contractility. Considering that EMD 60263 reversed both causes of oxygen wastage, it is most likely that this drug increases myofibrillar Ca(2+)-sensitivity without increasing myofibrillar cross-bridge cycling.

In vivo evidence that EMD 57033 restores myocardial responsiveness to intracoronary Ca(2+) in stunned myocardium

Despite ample in vitro evidence that myofilament Ca(2+)-responsiveness of stunned myocardium is decreased, in vivo data are inconclusive. Conversely, while Ca(2+)-sensitizing agents increase myofilament Ca(2+)-responsiveness in vitro, it has been questioned whether this also occurs in vivo. We therefore tested in open-chest anesthetized pigs whether EMD 57033 (the (+) enantiomer of 5-[1-(3,4-dimethoxybenzoyl)-1,2,3, 4-tetrahydro-6-quinolyl]-6-methyl-3,6-dihydro-2H-1,3, 4-thiadiazin-2-one) increases responsiveness to Ca(2+) of non-stunned myocardium and restores function of stunned myocardium by normalizing the responsiveness to Ca(2+). Studies were performed under beta-adrenoceptor blockade to minimize the contribution of the phosphodiesterase-III inhibitory actions of EMD 57033. Consecutive intracoronary Ca(2+) infusions were used to evaluate the contractile response (assessed by the left ventricular end-systolic elastance, E(es)) to added Ca(2+) of non-stunned myocardium and myocardium stunned by 15 min coronary artery occlusion and 30 min reperfusion. In non-stunned propranolol-treated myocardium, the Ca(2+) infusions doubled E(es) (baseline 6.9+/-0.9 mmHg mm(-2), n=8). Following Ca(2+)-washout, subsequent EMD 57033 infusion (0.1 mg kg(-1) min(-1), i.v.) tripled E(es) (P<0.05) and potentiated the Ca(2+)-induced increase in E(es) to 55.7+/-10.0 mmHg mm(-2) (P<0.05). Stunning (n=7) decreased E(es) to 5.3+/-0.6 mmHg mm(-2) (P>0.10) and attenuated the Ca(2+)-induced increase in E(es) (P<0.05). Subsequent infusion of EMD 57033 increased E(es) to 6.8+/-1.8 mmHg mm(-2) (P<0. 05) and restored responsiveness to added Ca(2+). These in vivo findings are consistent with the in vitro observations that myofilament Ca(2+)-responsiveness of stunned myocardium is reduced and that EMD 57033 increases contractility by enhancing myofilament Ca(2+)-responsiveness.

Efficiency of energy transfer, but not external work, is maximized in stunned myocardium

There is no evidence regarding the effect of stunning on maximization of regional myocardial external work (EW) or efficiency of energy transfer (EET) in relation to regional afterload (end-systolic stress, sigma(es)). To that end, we studied these relationships in both the left anterior descending coronary artery (LADCA) and left circumflex coronary artery regions in anesthetized, open-chest pigs before and after LADCA stunning. In normal myocardium, EET vs. sigma(es) was maximal at 75.4 (69.7-81.0)%, whereas EW vs. sigma(es) was submaximal at 12.0 (6.61-17.3) x 10(2) J/m(3). Increasing sigma(es) increased EW by 18 (10-27)%. Regional myocardial stunning decreased EET (27%) and EW (36%) and caused the myocardium to operate both at maximal EW (EW(max)) and at maximal EET (EET(max)). EET and EW became also more sensitive to changes in sigma(es). In the nonstunned region the situation remained unchanged. Combining the data from before and after stunning, both EW(max) and EET(max) displayed a positive relationship with contractility. In conclusion, the normal regional myocardium operated at maximal EET rather than at maximal EW. Therefore, additional EW could be recruited by increasing regional afterload. After myocardial stunning, the myocardium operated at both maximal EW and maximal EET, at the cost of increased afterload sensitivity. Contractility was a major determinant of this shift.