Evaluating the value of the timing of recurrence during blanking period after atrial fibrillation ablation

Introduction

In the first weeks after atrial fibrillation (AF) ablation, the arrythmia may recur theoretically due to transient local inflammation and not due to treatment failure. This is defined as the blanking period, with a proposed duration of 3 months. Recently, this time period has been brought into question. The aim of this work was to evaluate the correlation between the timing of blanking recurrence and late AF recurrence.

Methods

This was a single-centre retrospective study including patients without structural heart disease that underwent first AF ablation and were subsequently enrolled in the post ablation structured program between 2018 and 2021. Patients were excluded if they had <6 months follow-up. Appointment with ECG and Holter monitoring was performed at 1, 3, 6 and 12 months after ablation.

Results

We included a total of 193 patients (56% male, mean age 63±12 years). Of these, 79% had paroxysmal AF and mean left atrial volume index was 58±18 mL/m2. During the 3-month blanking period, there were 39 (21%) recurrences, 18 (9%) of which in the first month. After blanking period, at 6 months, 25 (13%) patients had AF recurrence, 56% of which had already recurred during blanking period. AF recurrence in the 2nd and 3rd month of blanking increased the odd of recurrence at 6-month by more than 5-fold (odds ratio (OR) 8,944; CI 95% 2,817–28,400, p<0.001 and OR 5,591; 95% CI 1,173–26,651; p=0.031). On the other hand, recurrence of AF during the 1st month of blanking was not associated with increased chance of 6-month AF recurrence (OR 2,095, 95% CI 0,630–6,964, p=0.227) (figure 1). There were no significant differences in clinical variables, including LA volume, between patients with 1-month recurrence and patients without recurrences. However, patients with AF recurrence in the 2nd and 3rd month of blanking had significantly increased LA volume.

Conclusion

Our study suggests that patients with AF recurrence in the 2nd and 3rd month of blanking have structurally different atria and are at a significantly higher risk of post blanking AF recurrence, in contrast with patients with AF recurrence in the 1st month of blanking, thus questioning the appropriate duration of the blanking period.

Funding Acknowledgement

Type of funding sources: None.

Further prognostic stratification in patients with oscillatory ventilation with exercise: is there more to it than just ups and downs?

Introduction

Exercise Oscillatory Ventilation (EOV) has numerous definitions, but the common foundation is the presence of an oscillatory phenomenon of the ventilation/minute graph with a given amplitude and frequency. Recently, it was proposed that the presence of a delay in O2 consumption (VO2) peak to minute ventilation (VE) peak during ventilatory oscillation was a predictor of worse prognosis in patients with heart failure (HF) and left ventricular ejection fraction (LVEF) <50%.

The aim of this work was to assess whether these characteristics add further prognostic value to the subset of patients with HF and EOV.

Methods

This was a single-centre retrospective cohort of consecutive patients with HF and LVEF <50% that underwent cardiopulmonary exercise testing (CPET) from 2016–2020. EOV was defined as per Vainshelboim 2017 (≥3 consecutive cyclic fluctuations of ventilation during exercise, average amplitude over 3 ventilatory oscillations ≥5L and an average length of three oscillatory cycles 40s to 140s). The presence of EOV was evaluated by 3 independent observers after observing a VE over time plot. For the creation of this plot, data was collected as a rolling average of 5 consecutive breaths. The presence of EOV was established if at least 2 observers agreed on the classification.

Afterwards, a second graph was plotted, with both VO2 and VE over time and the mean delay between VO2 peak to VE peak during EOV was manually calculated (Figure 1).

The primary endpoint was a composite of time to all-cause death, heart transplantation or left ventricular assistance device (LVAD) implantation.

Results

Of the 285 patients, 78 (27%) were classified as having EOV. These HF patients were mostly male (75%) with a mean age of 58±12 years, mean LVEF 31±10% with 63% having ischemic etiology. During a median follow up of 27 (17 to 43) months, 4 LVAD implantations, 12 heart transplantations and 18 deaths. The rate of primary outcome was 19% and 36% at 1- and 2-years. The amplitude, frequency, and maximum number of EOV cycles were not associated with the development of the primary endpoint. Only the mean delay between VO2 peak to VE peak during EOV was predictive of time to primary endpoint, even when adjusted for peak VO2 and VE VCO2 slope (adjusted HR 1.06 95% CI 1.009–1.114) (Figure 2). The cut-off of 5 seconds for mean VO2 peak to VE peak delay seems to be the most useful to predict the primary outcome at 2 years, with a sensitivity of 48% and specificity of 84%.

Conclusion

This novel parameter seems to be the only EOV-related parameter to enable further stratification of prognosis in a cohort of patients with severe HF, with the best cut-off of mean delay between VO2 peak to VE peak during EOV being 5 seconds.

Funding Acknowledgement

Type of funding sources: None.

Late gadolinium enhancement is a strong predictor of life threatening arrhythmias in patients with dilated cardiomyopathy undergoing ICD implantation for primary prevention of sudden cardiac death

Background

The usefulness of implantable cardioverter defibrillators (ICD) for primary prevention of arrhythmic sudden cardiac death (SCD) in patients with non-ischemic dilated cardiomyopathy (DCM) has been questioned. Efforts to improve risk stratification have included scores such as the “MADIT-ICD benefit score”, and the use of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

The purpose of this study was to evaluate the potential usefulness of these two tools to assess the risk of life-threatening arrhythmias in patients with non-ischemic DCM undergoing ICD implantation for primary prevention of SCD.

Methods

We conducted a single-center retrospective study of consecutive patients who underwent contrast-enhanced CMR before ICD implantation for primary prevention of SCD. Patients with ischemic cardiomyopathy were used as reference. Patients with non-dilated cardiomyopathies were excluded.

The arrhythmic component of the MADIT-ICD benefit score (VT/VF score) was calculated for each patient, and considered high if ≥7, as recommended.

The primary endpoint was the occurrence of SCD or life-threatening arrhythmias (VF or VT >200 bpm). Follow-up was performed by device interrogation in all patients except those who suffered SCD.

Results

A total of 151 patients (93 ischemic, mean age 62±13 years, 75% male) with mean left ventricular ejection fraction (LVEF) of 27±8% were included. Overall, 72% (n=67) ischemic and 45% (n=26) non-ischemic patients had scores ≥7 and were considered high-risk. LGE was present in all patients with ischemic cardiomyopathy, and in 76% (n=44) of patients with non-ischemic DCM.

During a median follow-up of 21 (8–38) months, 21 patients (13.9%, 11 ischemic and 10 non-ischemic) met the primary endpoint.

Overall, the event-free survival of non-ischemic patients was similar to that of ischemic patients (log rank p=0.269). In patients with non-ischemic DCM, there were 7 arrhythmic events (26.9%) in those with MADIT-ICD VT/VF scores ≥7, and 3 events (9.4%) in those with scores <7 (log rank p=0.104).

In the same population, there were 10 arrhythmic events (23%) in patients with LGE, but no events in patients without LGE (log rank p=0.036).

LVEF was similar in patients with and without arrhythmic events (26±8% vs. 27±7%, p=0.717), and in those with and without LGE (26±7% vs. 28±9%, p=0.342).

Conclusion

The presence of LGE is a strong predictor of life threatening arrhythmias in patients in non-ischemic DCM undergoing ICD implantation for primary prevention, seemingly outperforming the clinical MADIT-ICD benefit score.

Funding Acknowledgement

Type of funding sources: None.

Exercise oscillatory ventilation disturbances: finding order amongst chaos

Background

Exercise Oscillatory Ventilation (EOV) during Cardiopulmonary Exercise Test (CPET) predicts prognosis in patients with Heart Failure (HF). In these patients, O2 consumption (VO2) oscillations have also been described, possibly secondary to circulatory delay. We hypothesize that in clinically meaningful EOV, cardiac output variation is mirrored by VO2 oscillation, which is then chronologically followed by a similar oscillation in minute ventilation (VE) (Figure 1). Accordingly, we aimed to assess whether this new definition surpassed that of classical EOV.

Methods

This is a single-centre cohort study of consecutive patients undergoing CPET from 2016 to 2018. Patients with LVEF >50% were excluded. CPET was performed on a treadmill to the limit of tolerance. Data was collected as a rolling average of 20 seconds and a composite VE/time and VO2/time plot was created. Classical EOV was defined as three or more regular oscillations of the VE graph with a minimal average amplitude of five litters. The addition of exercise VO2-to-VE peak-to-peak ventilation asynchrony (EVA) to the previous criteria fulfilled the new definition. The primary endpoint was a composite of time to all-cause death, heart transplantation or HF hospitalization.

Results

Overall, 177 patients were enrolled (mean age 58±11 years, LVEF 34±9%), of whom 35 had EOV and 17 had EVA. Compared to those without EVA, patients with EVA had markers of more severe HF. During a median follow-up of 32 (21–42) months, 55 patients met the primary outcome (32 all-cause deaths, 15 heart transplants, 47 HF hospitalizations). In multivariate analysis, EVA was associated with a 2.5-fold increased risk of events (HR 2.489; 95% CI: 1.302–4.759; p=0.006), adjusted for peak VO2, VE to CO2 production ratio (VE/VCO2 slope) and LVEF. EVA outperformed EOV in predicting the primary endpoint at 1 year, with a similar sensitivity and higher specificity (96.2 vs. 83.2%). The rate of events between the subgroup of patients without EVA was similar regardless of presence of EOV, contrasting with a higher rate in the EVA subgroup (Figure 2).

Conclusion

EVA is a strong predictor of hard outcomes in a broad population with HF. The new definition may outperform that of classical EOV. The incidence and prognostic value of EVA in the management algorithm and risk stratification of patients with HF is worth being further explored.

Funding Acknowledgement

Type of funding sources: None.

Looking beyond left ventricular ejection fraction – a new multiparametric CMR score to refine the prognostic assessment of HF patients

Background

Cardiac magnetic resonance (CMR) is recommended in Heart Failure (HF) to assess myocardial structure and function. Recently, the quantification of pulmonary congestion and skeletal muscle mass using CMR have been shown to predict adverse events in HF, but a tool integrating this information is currently unavailable. The purpose of this study was to develop and test a new multiparametric CMR-derived score.

Methods

We conducted a single-center retrospective study of consecutive HF patients with left ventricular ejection fraction (LVEF) <50% who underwent CMR. Several CMR parameters with known prognostic value were assessed, including: LVEF, Lung Water Density (LWD), Pectoralis Major Muscle (PMM) area, and presence of Late Gadolinium Enhancement. PMM area was outlined at the level of the carina – Figure 1A, B – and LWD was defined as the lung-to-liver signal ratio multiplied by 0.7, as previously described. Both parameters were measured in standard HASTE images - Figure 1C. The primary endpoint was a composite of all-cause death or HF hospitalization. Using the Cox regression Hazard Ratios of designated variables, a risk score was developed.

Results

Overall, 436 patients were included. During a median follow-up of 27 (17–37) months, 43 (9.9%) patients died and 57 (13.2%) had at least one hospitalization for HF. LVEF, LWD and PMM were independent predictors of the primary endpoint and were included in the CMR-HF score – Figure 2. The annual rate of events increased from 4.7 to 7.5 and 20.0% from lowest to highest tertile of the score. Roughly half of the events (54%) occurred in patients in the highest tertile of the CMR-HF score. In multivariate analysis, the new score independently predicted the primary endpoint (HR per 5 points: 1.54; 95% CI: 1.21–1.97; p<0.001) even after adjustment for age, body mass index, NYHA class, NT-proBNP, estimated glomerular filtration rate, presence of implantable cardioverter-defibrillator, and ischemic etiology.

Conclusions

This novel multidimensional CMR-HF score, combining easily obtainable data on left ventricular pump failure, lung congestion and muscular wasting, is a promising tool identifying HF patients with an LVEF <50% at higher risk of death or HF hospitalization.

Funding Acknowledgement

Type of funding sources: None.

1098 Atrial thickening: a surprisingly "gouty" heart

Case Presentation

A 49 year-old male presented to the emergency department with fever and lower limb myalgia for 5 days. His past history was notable for acute episodes of microcrystalline pyrophosphate oligoarthritis for which he was receiving allopurinol 100mg, colchicine 1mg and prednisolone 5mg. Physical examination was unrevealing. Laboratory workup showed normocytic normochromic anemia (Hb 12.8g/dL), leukocytosis (22 490 /mm3), neutrophilia (86.8%), increased C-reactive protein (CRP

26mg/dL), low procalcitonin (0.82ng/mL) and mildly elevated creatinine-kinase (83 UI/L). The patient was admitted with fever of unknown origin and started on ceftriaxone after blood and urine cultures.

He remained febrile with persistently heightened inflammation. Cultures, infectious and auto-immune tests, bone marrow biopsy, myelogram and abdominopelvic CT scan were negative. Three weeks later, syncope due to complete atrioventricular (AV) block led to temporary pacemaker implantation. Transoesophageal echocardiography (TOE) revealed a left atrial (LA) wall thickening,

evident on MRI as an 8-10mm T2-hyperintensity sign, with right atrial (RA) and ventricular sparing. PET/CT scan showed an 18F FDG uptake exclusively in the LA. As a neoplasia was highly suspected, a transspeptal biopsy was attempted, yet the sample was scarce for analysis. Thus, a biopsy via sternotomy was performed, now sampling both the LA and RA. Indeed, repeated TOE showed de novo RA involvement with a prominent nodular finding (19x24mm) in the lateral wall.

Myocyte inflammation and necrosis accompanied with granulocyte infiltration (mostly neutrophils but also eosinophils) was observed in all samples. There were no findings suggestive of neoplasia. The patient was still on allopurinol, which has been reported to involve the myocardium in a late (type IV) hypersensitivity reaction (the so-called DRESS syndrome), even in the absence of systemic inflammation. Thus, allopurinol was stopped and 1mg/Kg prednisolone was started. The patient

significantly improved and was discharged home with negative CRP the following two weeks. After 1 month, MRI was repeated and no atrial inflammation was found. After 4 months follow-up, he is doing well on 2.5mg of prednisolone and febuxostat 80mg.