Machine Learning in Cardiology: A Potential Real-World Solution in Low- and Middle-Income Countries.

Artificial intelligence (AI) and machine learning (ML) is a promising field of cardiovascular medicine. Many AI tools have been shown to be efficacious with a high level of accuracy. Yet, their use in real life is not well established. In the era of health technology and data science, it is crucial to consider how these tools could improve healthcare delivery. This is particularly important in countries with limited resources, such as low- and middle-income countries (LMICs). LMICs have many barriers in the care continuum of cardiovascular diseases (CVD), and big portion of these barriers come from scarcity of resources, mainly financial and human power constraints. AI/ML could potentially improve healthcare delivery if appropriately applied in these countries. Expectedly, the current literature lacks original articles about AI/ML originating from these countries. It is important to start early with a stepwise approach to understand the obstacles these countries face in order to develop AI/ML-based solutions. This could be detrimental to many patients' lives, in addition to other expected advantages in other sectors, including the economy sector. In this report, we aim to review what is known about AI/ML in cardiovascular medicine, and to discuss how it could benefit LMICs.

Post Procedural Peak Left Atrial Contraction Strain Predicts Recurrence of Arrhythmia after Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Left atrial (LA) function can be impaired by the atrial fibrillation (AF) ablation and might be associated with the risk of recurrence. We sought to determine whether the post-procedural changes in LA function impact the risk of recurrence following AF ablation. METHODS: We retrospectively reviewed patients who underwent AF ablation between 2009 and 2011 and underwent transthoracic echocardiography before ablation, 1-day and 3-month after ablation. Peak left atrial contraction strain (PACS) and left atrial emptying fraction (LAEF) were evaluated during sinus rhythm and compared across the three time points. The primary endpoint was atrial tachyarrhythmia recurrence after ablation. RESULTS: A total of 144 patients were enrolled (mean age 61 ± 11 years, 77% male, 46% persistent AF). PACS and LAEF initially decreased 1-day following ablation but partially recovered within 3 months in PAF patients, with a similar trend in the PerAF patients. After median 24 months follow-up, 68 (47%) patients had recurrence. Patients with recurrence had higher PACS1-day than that in non-recurrence subjects (-10.9 ± 5.0% vs. -13.4 ± 4.7%, p = 0.003). PACS1-day -12% distinguished recurrence cases with a sensitivity of 67.7% and specificity of 60.5%. The Kaplan-Meier curves showed significant difference in 5-year cumulative probability of recurrence between those with PACS ≥ -12% and PACS < -12% (log rank p < 0.0001). Multivariate regression showed that PACS1-day was an independent risk factor of arrhythmia recurrence. CONCLUSIONS: Left atrial function deteriorates immediately following AF ablation and partially recovers in 3 months but remains abnormal in the majority of patients. PACS1-day post procedure predicts arrhythmia recurrence at long-term follow-up.

Management of the Patient With Patent Foramen Ovale in 2021: A Spectrum of Cases.

Patients with patent foramen ovale can manifest in a variety of ways. These presentations and their resolution are discussed in this article.

Von Willebrand Factor and ADAMTS13 as Predictors of Adverse Outcomes in Patients With Nonvalvular Atrial Fibrillation.

BACKGROUND: Von Willebrand factor (VWF) elevation correlates with the left atrial blood stasis in nonvalvular atrial fibrillation (NVAF). However, the long-term impact of elevated VWF in patients with NVAF is not well established. METHODS: To assess the impact of VWF and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) in conjunction with echocardiographic measures of left atrium blood stasis on clinical outcomes, 414 NVAF prospectively recruited (October 4, 2007, to April 27, 2009) patients were followed for 3 years. VWF antigen, VWF activity, ADAMTS13 activity, and echocardiographic findings were assessed at baseline. Thromboembolism (TE) (stroke/transient ischemic attack (TIA)), myocardial infarction, or TE of other locations), major bleeding, clinically relevant nonmajor bleeding, and all-cause mortality were assessed by clinical follow-up, questionnaire, or telephone communication. RESULTS: Among 374 patients (mean age, 63.4 ± 12.7 years; 25% females) who had complete follow-up data, there were 33 TE in 32 patients (8.6%), 18 deaths (5.1%), and 33 bleeding events (21 major bleeding and 12 clinically relevant nonmajor bleeding) in 25 patients (6.7%). VWF antigen was predictive of TE in the univariate examination (hazard ratio [HR]: 1.007, 95% confidence interval [CI]: 1.002, 1.013, P = 0.011) but not in multivariate analysis. VWF was an independent predictor of all-cause mortality (HR: 1.011, 95% CI: 1.003, 1.020, P = 0.011) and a composite of TE and all-cause mortality (HR: 1.006, 95% CI: 1.001, 1.012, P = 0.039) in multivariate analysis. ADAMTS13 was not predictive of clinical outcomes in multivariate analysis. CONCLUSIONS: Among patients with NVAF, VWF is an independent predictor of poor outcomes including death and a composite of death and TE. As such, VWF measure may help identify high-risk patients and provide further stratification beyond CHA2DS2-VASc assessment.

CONTEXTE: Une élévation du facteur de Von Willebrand (FVW) concorde avec une stase sanguine dans l'oreillette gauche dans la fibrillation auriculaire non valvulaire (FANV). Les répercussions à long terme d'un taux élevé du FVW chez les patients présentant une FANV ne sont toutefois pas bien établies. MÉTHODOLOGIE: Pour évaluer les répercussions sur les résultats cliniques du FVW et d'une désintégrine et métalloprotéinase de motif type 1 (ADAMTS13) conjointement avec les mesures échocardiographiques de la stase sanguine dans l'oreillette gauche, 414 patients atteints de FANV ont été inscrits de façon prospective (du 4 octobre 2007 au 27 avril 2009) pour faire l'objet d'un suivi de 3 ans. L'antigène du FVW, l'activité du FVW, l'activité d'ADAMTS13, et les résultats de l'échocardiographie ont été évalués au départ. La thromboembolie (TE) (accident vasculaire cérébral/accident ischémique transitoire, infarctus du myocarde, ou TE survenant ailleurs), l'hémorragie majeure, l'hémorragie non majeure pertinente sur le plan clinique et la mortalité toutes causes ont été évaluées au suivi clinique, par questionnaire, ou lors d'un appel téléphonique. RÉSULTATS: Parmi les 374 patients (âge moyen : 63,4 ± 12,7 ans; 25 % de femmes) ayant participé au suivi jusqu'à sa fin, on a relevé 33 TE chez 32 patients (8,6 %), 18 décès (5,1 %) et 33 événements hémorragiques (21 hémorragies majeures et 12 hémorragies non majeures pertinentes sur le plan clinique) chez 25 patients (6,7 %). L'antigène du FW était prédictif d'une TE selon l'analyse univariée (risque relatif [RR] : 1,007; intervalle de confiance [IC] à 95 % : de 1,002 à 1,013; p = 0,011), mais non selon l'analyse multivariée. Le FVW était un facteur prédictif indépendant de la mortalité toutes causes (RR : 1,011; IC à 95 % : de 1,003 à 1,020; p = 0,011) et des événements regroupés de TE et de mortalité toutes causes (RR : 1,006; IC à 95 % : de 1,001 à 1,012; p = 0,039) dans l'analyse multivariée. La protéase ADAMTS13 ne constituait pas un facteur prédictif des résultats cliniques dans l'analyse multivariée. CONCLUSIONS: Parmi les patients présentant une FANV, le FVW était un facteur prédictif indépendant de résultats défavorables, notamment de décès et des événements regroupant les décès et la TE. La mesure du FVW pourrait donc aider à cibler les patients à risque élevé, et permettre une stratification au-delà de l'évaluation du score CHA2DS2-VASc.

A Challenging Combination: Anomalous Left Anterior Descending Coronary Artery, Myocardial Bridging, and Endothelial Dysfunction.

50 years old female patient with a medical history of hypertension presented to the clinic with chest pain, palpitations, and dyspnea on exertion of 2 years duration. Extensive workup in search of the culprit etiology of her chest pain revealed a challenging combination of an anomalous left anterior descending artery with myocardial bridging and endothelial dysfunction. She was treated medically with long acting nitrates, L-arginine and calcium channel blockers, and remains asymptomatic after 12 months of follow up.

Determinants of Sudden Cardiac Death in Adult Patients With Eisenmenger Syndrome.

Background Patients with Eisenmenger syndrome are known to have a high incidence of sudden cardiac death (SCD), yet the underlying causes are not well understood. We sought to define the predictors of SCD in this population. Methods and Results A retrospective analysis of all patients with Eisenmenger syndrome from 2 large tertiary referral centers was performed. ECGs, prolonged ambulatory recordings, echocardiograms, and clinical histories were reviewed; and the cause of death was identified. A total of 246 patients (85 [34.6%] men) with a mean age of 37.3 (±14.2) years were followed up for a median of 7 years. Over the study period, 136 patients died, with 40 experiencing SCD and 74 experiencing cardiac death (sudden and nonsudden). Age, atrial fibrillation, prolonged QRS duration, complete heart block, right atrial enlargement, right bundle branch block, increased right atrial pressure, impaired biventricular function, and the presence of a pacemaker were associated with increased risk of SCD, whereas advanced pulmonary hypertension therapies were protective. Atrial fibrillation (11.45-fold increased risk; P<0.001) and QRS duration ≥120 ms (2.06-fold increased risk; P=0.034) remained significant predictors of SCD in the multivariate analysis, whereas advanced pulmonary hypertension therapies were strongly protective against SCD (P<0.001). Conclusions Atrial arrhythmias, impaired ventricular function, and conduction system disease were associated with increased risk of SCD in this cohort of patients with Eisenmenger syndrome, providing an opportunity for early risk stratification and potential intervention. Clinical heart failure symptoms (New York Heart Association class ≥II) were predictive of increased mortality but not of SCD, suggesting a potential arrhythmic cause behind SCD.

Left Ventricular Remodeling After Transcatheter Versus Surgical Therapy in Adults With Coarctation of Aorta.

OBJECTIVES: The purpose of this retrospective cohort study was to compare remodeling of left ventricular (LV) structure and function after transcatheter stent therapy with remodeling of LV structure and function after surgical therapy for COA. BACKGROUND: Transcatheter stent therapy is as effective as surgery in producing acute hemodynamic improvement in patients with coarctation of aorta (COA). However, LV remodeling after transcatheter COA intervention has not been systematically investigated. METHODS: LV remodeling was assessed at 1, 3, and 5 years post-intervention by using LV mass index (LVMI), LV end-diastolic dimension, LV ejection fraction, LV global longitudinal strain (LVGLS), LV mitral annular tissue Doppler early velocity (LVe'), and ratio of mitral inflow pulsed wave Doppler early velocity and e' (E/e') ratio. RESULTS: There were 44 patients in the transcatheter group and 128 patients in the surgical group. Compared to the surgical group, the transcatheter group had less regression of LVMI (-4.6; 95% confidence interval [CI]: -5.5 to -3.7 vs. -7.3; 95% CI: -8.4 to -6.6 g/m2; p < 0.001), less improvement in LVGLS (2.1; 95% CI: 1.8 to 2.4 vs. 2.9; 95% CI: 2.6 to 3.2%; p = 0.024), and in e' (1.0 ; 95% CI: 0.7 to 1.2 vs. 1.5 ; 95% CI: 1.3 to 1.7 cm/s; p = 0.009) at 5 years post-intervention. Exploratory analysis showed a correlation between change in LVMI and LVGLS, and between change in LVMI and mitral annular tissue Doppler early velocity (e'), and this correlations were independent of the type of intervention received. CONCLUSIONS: Transcatheter stent therapy was associated with less remodeling of LV structure and function during mid-term follow-up. As transcatheter stent therapy becomes more widely used in the adult COA population, there is a need for ongoing clinical monitoring to determine if these observed differences in LV remodeling translate to differences in clinical outcomes.

Transcatheter closure of coronary artery fistula: A 21-year experience.

OBJECTIVES: To evaluate the outcomes of transcatheter coronary artery fistula (CAF) closure and to identify anatomic/procedural factors that may impact outcomes. BACKGROUND: Due to the rarity of CAF, reported experience with transcatheter closure remains limited and anatomic and procedural factors that may lead to unsuccessful closure, complications, or recanalization of CAF are unclear. METHODS: All patients who underwent transcatheter CAF closure at Mayo Clinic from 1997 to 2018 were retrospectively reviewed. CAF anatomic characteristics, procedural techniques, and clinical/angiographic outcomes were assessed. RESULTS: A total of 45 patients underwent transcatheter closure of 56 CAFs. The most commonly used devices were embolization coils in 40 (71.4%) CAFs, vascular occluders in 10 (17.8%), or covered stent in 2 (3.6%). Acute procedural success with no or trivial residual flow occurred in 50 (89.3%) CAFs. Residual flow was small in three (5.4%) and large in three (5.4%). Eight (17.8%) patients had complications, including device migration in three, intracranial hemorrhage from anticoagulation in one, and myocardial infarction (MI) in four. MI was a result of covered stent thrombosis or stagnation of flow after closure of large distal CAF. Twenty-two patients with 27 CAFs had follow-up angiography after successful index procedure at median time of 423 (IQ 97-1348) days. Of these, 23 (85.2%) had no/trace flow and 4 had large flow from recanalization. CONCLUSIONS: Transcatheter CAF closure is associated with a favorable acute procedural success and complication rate in selected patients. Procedural success and risk for complication are highly dependent on CAF anatomy and closure technique.

Left ventricular filling pressure in Tetralogy of Fallot: Correlation between invasive and noninvasive indices.

BACKGROUND: Left heart filling pressures, as measured by pulmonary artery wedge pressure (PAWP), is associated with heart failure related mortality. Because of the prognostic importance of PAWP, several echocardiographic indices have been proposed for noninvasive assessment of PAWP. However, these indices have not been validated in the congenital heart disease population. The purpose of this study was to determine the correlation between echocardiographic indices of PAWP, and the effect of high PAWP on transplant-free survival in adults with tetralogy of Fallot (TOF). METHODS: Retrospective study of adult TOF patients that underwent cardiac catheterization at Mayo Clinic, 1990-2017. We selected these pre-defined set of echocardiographic indices of LV diastolic function: mitral valve early velocity (E), mitral valve early and late velocity ratio (E/A), mitral valve deceleration time (DT), mitral annular tissue Doppler early velocity (e'), and left atrial volume index (LAVI). RESULTS: Of the echocardiographic indices analyzed among 213 patients (age 37 ± 14 years), only E velocity (ß = 5.83, standard error = 1.52, p < 0.001) and LAVI (ß = 0.14, standard error = 0.05, p = 0.007) correlated with PAWP. LAVI > 28 ml/m2 had sensitivity of 79% and specificity of 63% (AUC 0.712), and E velocity > 1.0 m/s had sensitivity of 66% and specificity of 89% (AUC 0.692), for detecting PAWP > 15 mmHg. LAVI > 28 ml/m2 was associated with reduced 10-year transplant-free survival (49% vs 90%, p < 0.001). CONCLUSION: This study supports the use of LAVI for noninvasive assessment of PAWP and for prognostication. Further studies are required to validate these results in a different population.

Single Coronary Artery Anomaly in a Woman With Acute ST-Segment Elevation Myocardial Infarction.

A 65-year-old woman presented with an acute inferior ST-segment elevation myocardial infarction and was found to have a rare single coronary artery anomaly on coronary angiography. A complete occlusion at the mid right coronary artery was identified as the culprit lesion and underwent successful percutaneous revascularization with stenting. (Level of Difficulty: Beginner.).

The applications and potential limitations of right ventricular volumes as surrogate marker in tetralogy of fallot.

Cardiac magnetic resonance imaging derived right ventricular (RV) volumes are often necessary for optimal timing of pulmonary valve replacement in patients with tetralogy of Fallot (TOF). This practice is based on previous studies that reported preoperative RV volumetric thresholds that predicted postoperative RV remodeling. As a result, pulmonary valve replacements are being performed even in asymptomatic patients based on RV volumetric thresholds that predict complete postoperative RVOT remodeling. Hence, RV volumes are now being used as surrogate markers/endpoints for future cardiovascular outcomes. Unfortunately, there are no studies showing survival benefit for performing pulmonary valve replacement at smaller RV volumes. This review underscores some of the limitations of using RV volumes as surrogate markers for clinical outcomes, and also highlights knowledge gaps about the pathophysiologic mechanism of cardiovascular death in the TOF population.

Impact of atrial arrhythmia on survival in adults with tetralogy of Fallot.

BACKGROUND: Atrial arrhythmia is a late complication after tetralogy of Fallot (TOF) repair, but arrhythmia outcomes data are limited. OBJECTIVES: The purpose of the study was to describe atrial arrhythmia presentations, outcomes of antiarrhythmic therapy, and impact of arrhythmia on transplant-free survival. METHODS: We reviewed the MACHD (Mayo Adult Congenital Heart Disease) Registry and identified 113 patients (age 49 ±â€¯13 years) with documented arrhythmia, and 302 patients without history of arrhythmia, 1990-2017. We classified arrhythmias into atrial fibrillation and atrial flutter/tachycardia based on the rhythm on the first abnormal electrocardiogram. RESULTS: At the time of first documented arrhythmia, 58(51%) had atrial fibrillation while 55(49%) had atrial flutter/tachycardia. Of the 113 patients, 14(12%) received rhythm control with class I/III antiarrhythmic drugs (AAD), 79(70%) had direct current cardioversion, 9(8%) received rate control with class II/IV AAD, and 11(10%) received only anticoagulation. Successful cardioversion occurred in 100(89%) patients, and arrhythmia recurrence rate was 16 per 100 patient-years. The multivariate risk factors for death and/or heart transplant were atrial fibrillation (HR 1.94, CI 1.10-3.15, P = .031) and older age (HR 1.63, CI 1.12-2.43, P = .019) per 5 year increment. CONCLUSIONS: Atrial fibrillation, but not atrial flutter, was associated with reduced survival in our repaired TOF cohort. Further studies are required to determine if more aggressive antiarrhythmic therapy will improve survival in patients with atrial fibrillation.

Mild Coarctation of Aorta is an Independent Risk Factor for Exercise-Induced Hypertension.

Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with controls, patients with COA had a greater change in SBP per unit metabolic equivalent (ß=2.86; 95% CI, 1.96-4.77 versus 1.07, 95% CI, -0.15 to 1.75; P=0.018) and per unit oxygen pulse (ß=4.57; 95% CI, 2.97-7.12 versus 1.45, 95% CI, -0.79 to 2.09, P<0.001). There was a correlation between SBPpeak-SBPrest and elastance index (r=0.38, P=0.032) and between SBPpeak-SBPrest and total arterial compliance index (r=-0.51, P=0.001), suggesting an association between vascular dysfunction and exercise-induced BP changes. Patients with COA, without significant obstruction, had higher exercise-induced changes in SBP after adjustment for other risk factors for hypertension. Considering the already known prognostic importance of exercise-induced hypertension, the current study highlights the potential role of exercise testing for risk stratification of patients with mild COA.

Usefulness of Right Ventricular Volumetric and Afterload Indices for Risk Stratification in Patients With Tetralogy of Fallot.

Right ventricular (RV) volume overload due to chronic pulmonary regurgitation is the common mechanism for hemodynamic deterioration after tetralogy of Fallot (TOF) repair. As a result, RV volumetric indices are used for clinical risk stratification in this population. Since RV afterload is a determinant of RV hemodynamic performance, we hypothesized that afterload-adjusted RV volumetric indices will have a better correlation with disease severity compared with RV volumetric indices alone in patients with TOF. Cross-sectional study of adults with previous TOF repair that received care at Mayo Clinic, 2002-2015. We defined disease severity as atrial arrhythmia and/or impaired exercise capacity. We created afterload-adjusted RV volumetric indices by indexing these indices to RV systolic pressure (RVSP) as follows: RV end-diastolic volume (RVEDVi)/RVSP, RV end-systolic volume (RVESVi)/RVSP, and RV ejection fraction (RVEF)/RVSP. The RV volumetric indices were: RVEDVi 141 ± 43 ml/m2, RVESVi 79 ± 38 ml/m2, and RVEF 44 ± 10%, and RVSP was 48 ± 9 mm Hg. RVESVi was the only RV volumetric parameter that was associated with disease severity (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.01 to 1.32, p = 0.041) with area under the curve (AUC) of 0.612. In contrast RVEF/RVSP (OR 0.73, 95% CI 0.38 to 0.92, p = 0.037, AUC 0.649), and RVESVi/RVSP (OR 1.28, 95% CI 1.14-1.55, p = 0.008, AUC 0.798) were associated with disease severity. Compared with RV volumetric indices alone, the combined RV volumetric and afterload indices had better correlation with disease severity as measured by AUC. Afterload-adjusted RV volumetric indices had better correlation with disease severity, and may potentially improve risk stratification in this population.

Mechanism and Risk Factors for Death in Adults With Tetralogy of Fallot.

One of the goals of lifelong care in adults with tetralogy of Fallot (TOF) is early identification and treatment of patients at high risk for adverse events. Clinical risk stratification tools are critical for achieving this goal. We reviewed the Mayo Adult Congenital Heart Disease database and identified 465 TOF patients (age 37 ± 14 years, men 223 [48%]) seen at Mayo Clinic Rochester between 1990 and 2017. The aim was to determine the risk factors for death and/or heart transplant through a comprehensive analysis of 8 groups of variables (demographics, co-morbidities, medications, heart rhythm, echocardiography, cardiac magnetic resonance imaging, cardiac catheterization, and cardiopulmonary exercise test data) using univariable and multivariable Cox proportional hazard models. The end point of death and/or transplant occurred in 57 (12%) patients during a follow-up of 13.6 ± 8.2 years, yielding an event rate of 0.9% per year. Independent risk factors were age >42 years, atrial fibrillation, ≥moderate QRS fragmentation, left ventricular ejection fraction <50%, right ventricular end-diastolic pressure >16 mm Hg, and left ventricle end-diastolic pressure >16 mm Hg. There is nearly a twofold increase in the risk of death and/or transplant per unit increase in number of risk factors (hazard ratio 1.92, 95% confidence interval 1.62 to 2.27, p <0.001). In conclusion, the current study provides risk stratification indices based on a comprehensive risk model of all clinical variables in an unselected TOF population. Further studies are required to determine whether interventions targeted at modifying these risk factors will alter the annual event rate.

Long-term outcomes in adults with repaired tetralogy of Fallot and pulmonary atresia.

BACKGROUND: There are limited outcome data in adults with tetralogy of Fallot and pulmonary atresia. The purpose of this study was to describe re-operations and all-cause mortality in adults with tetralogy of Fallot and pulmonary atresia. METHODS: Retrospective review of adults with repaired tetralogy of Fallot and pulmonary atresia who received care at the Mayo Adult Congenital Heart Disease Clinic, 1990-2016. All-cause mortality was calculated as events per 100 patient-years from the time of first presentation to the Adult Congenital Heart Disease Clinic. RESULTS: Of the 221 patients, the age at initial tetralogy of Fallot repair was 6 (5-13) years, and the age at first presentation to the clinic was 27 - 8 years. All patients had at least one right ventricular to pulmonary artery conduit re-operation. There were 31 deaths (14%) at mean age of 41 - 14 years. The causes of death were end-stage heart failure (n = 17), sudden cardiac death (n=9), post-operative death after cardiac surgery (n = 2), sepsis with multi-system organ failure (n = 2), and unknown (n = 1). All-cause mortality rate was 1.7 per 100 patient-years. The risk factors for all-cause mortality were older age (>12 years) at the time of repair (hazard ratio 1.41, 95 confidence interval 1.06-2.02, p = 0.033), non-sustained ventricular tachycardia (hazard ratio 1.36, 95 confidence interval 1.17-2.47, p = 0.015), and left ventricular ejection fraction <50% (hazard ratio 1.39, 95 confidence interval 1.08-2.31, p = 0.031). CONCLUSION: Based on a review of 221 adults with repaired tetralogy of Fallot and pulmonary atresia, all patients had re-operations and all-cause mortality rate was 1.7 events per 100 patient-years. The current study provides important outcomes data for risk stratification in adults with tetralogy of Fallot and pulmonary atresia.

Assessment of Right Ventricular-Pulmonary Arterial Coupling in Chronic Pulmonary Regurgitation.

BACKGROUND: We hypothesized that noninvasively measured right ventricular (RV) to pulmonary arterial (RV-PA) coupling would be abnormal in chronic pulmonary regurgitation (PR) even in the setting of normal RV ejection fraction, and that RV-PA coupling indices would have a better correlation with peak oxygen consumption (VO2) compared with RV systolic indices alone. METHODS: This was a retrospective study of 129 adults (repaired tetralogy of Fallot [TOF] n = 84 and valvular pulmonic stenosis [VPS] with previous intervention n = 45) with ≥ moderate native PR and RV ejection fraction > 50%. The 84 TOF patients were propensity matched with 84 patients with normal echocardiogram (control); age 28 ± 7 years and male sex n = 39 (46%). RV-PA coupling was measured according to fractional area change (FAC)/RV systolic pressure (RVSP) and tricuspid annular plane systolic excursion (TAPSE)/RVSP. RESULTS: RV systolic function indices were similar between TOF and control groups (FAC 43 ± 6% vs 41 ± 5% [P = 0.164] and TAPSE 22 ± 5 mm vs 24 ± 6 mm [P = 0.263]). However, RV-PA coupling was lower in the TOF group (FAC/RVSP 1.10 ± 0.29 vs 1.48 ± 0.22 [P < 0.001]; TAPSE/RVSP 0.51 ± 0.15 vs 0.78 ± 0.11 [P < 0.001]) because of higher RV afterload (RVSP 42 ± 3 mm Hg vs 31 ± 3 mm Hg [P = 0.012]). FAC/RVSP (r = 0.61; P < 0.001) and TAPSE/RVSP (r = 0.69; P < 0.001) correlated with peak VO2 especially in the patients with impaired exercise capacity whereas FAC and TAPSE were independent of peak VO2. Similar comparisons between VPS and control groups showed no difference in TAPSE and FAC between groups, but lower FAC/RVSP and TAPSE/RVSP in the VPS group. CONCLUSIONS: There is abnormal RV-PA coupling in chronic PR, and noninvasively measured RV-PA coupling might potentially be prognostic because of its correlation with exercise capacity.

Outcomes of Pregnancy in Patients With Prior Right Ventricular Outflow Interventions.

Background The purpose of this study was to compare the incidence of pregnancy-related adverse outcomes ( PRAO ) between patients with versus without hemodynamically significant right ventricle outflow tract ( RVOT) . Methods and Results This was a retrospective cohort study of all pregnant patients with isolated RVOT lesions undergoing evaluation at the Mayo Clinic, 1990 to 2017. Hemodynamic significance was defined as ≥moderate pulmonary/conduit stenosis (≥3 m/s) and/or ≥moderate regurgitation. Patients with concomitant significant left heart disease were excluded. PRAO was defined as cardiovascular, obstetric, and/or neonatal complications occurring during the pregnancy through 6 weeks postpartum. A total of 224 pregnancies in 114 patients with RVOT lesions were identified; 38 pregnancies occurred in 24 patients with hemodynamically significant RVOT . Forty-eight (21%) pregnancies ended in spontaneous abortion. Of the 173 completed pregnancies, median gestational age at delivery was 38 (35-40) weeks and median birth weight 2965 (2065-4122) g. Seven pregnancies (4%) were complicated by cardiovascular events, 14 (8%) by obstetric complications, with adverse neonatal outcomes occurring in 38 (22%). There were no maternal deaths. The incidence of spontaneous abortion and PRAO were similar in both the RVOT and hemodynamically significant RVOT groups. As an isolated condition, Tetralogy of Fallot-pulmonary atresia was associated with spontaneous abortion and neonatal complications. Conclusions The risk of cardiovascular complications was low in patients with isolated RVOT lesions, and hemodynamically significant RVOT lesions were not associated with either cardiovascular complications or PRAO . Further studies are required to explore the factors responsible for PRAO in patients with Tetralogy of Fallot-pulmonary atresia.

Atrial Fibrillation Therapy and Heart Failure Hospitalization in Adults With Tetralogy of Fallot.

OBJECTIVES: This study hypothesized that atrial fibrillation was associated with heart failure (HF) hospitalization, and that patients who received rhythm control therapy had a lower incidence of HF hospitalization and mortality. BACKGROUND: Atrial fibrillation is a known risk factor for HF hospitalization and mortality in patients with acquired heart disease. Although atrial arrhythmias are common in adults with tetralogy of Fallot (TOF), data about prevalence and outcomes of therapy for atrial fibrillation are very limited. METHODS: The MACHD (Mayo Adult Congenital Heart Disease) database was queried for adults with repaired TOF and documented atrial fibrillation from 1990 to 2017. Primary endpoint was HF hospitalization defined as admission for volume overload (pulmonary congestion and/or peripheral edema) requiring intravenous diuretics. Secondary endpoint was the effect of rhythm control therapy on HF hospitalization and all-cause mortality. Patients were divided into rhythm control and rate control groups based on the therapy initiated at the time of arrhythmia diagnosis. RESULTS: Of 415 patients, 27 (7%) had 42 HF hospitalizations. Of these 415 patients, 88 (21%) had atrial fibrillation at age 49 ± 13 years. Atrial fibrillation was an independent risk factor for HF hospitalization (adjusted hazard ratio: 2.67; 95% confidence interval: 1.04 to 7.34; p = 0.045). The 88 patients were divided into the rhythm control group (n = 61, 69%) and the rate control group (n = 27, 31%). The rate control group had higher unadjusted annual incidence of HF hospitalization (13% vs. 3%; p = 0.001) and all-cause mortality (11% vs. 4%; p = 0.002). CONCLUSIONS: Atrial fibrillation was a risk factor for HF hospitalization and mortality in TOF patients, and rhythm control therapy was protective against these adverse events.

Direct Current Cardioversion of Atrial Arrhythmias in Adults With Cardiac Amyloidosis.

BACKGROUND: Arrhythmias, conduction abnormalities, and intracardiac thrombus are common in patients with cardiac amyloidosis (CA). Outcomes of direct-current cardioversion (DCCV) for atrial arrhythmias in patients with CA are unknown. OBJECTIVES: This study sought to examine DCCV procedural outcomes in patients with CA. METHODS: Patients with CA scheduled for DCCV for atrial arrhythmias from January 2000 through December 2012 were identified and matched 2:1 with control patients by age, sex, type of atrial arrhythmia, and date of DCCV. RESULTS: CA patients (n = 58, mean age 69 ± 9 years, 81% male) were included. CA patients had a significantly higher cardioversion cancellation rate (28% vs. 7%; p < 0.001) compared with control patients, mainly due to intracardiac thrombus identified on transesophageal echocardiogram (13 of 16 [81%] vs. 2 of 8 [25%]; p = 0.02); 4 of 13 of the CA patients (31%) with intracardiac thrombus on transesophageal echocardiogram received adequate anticoagulation ≥3 weeks and another 2 of 13 (15%) had arrhythmia duration <48 h. DCCV success rate (90% vs. 94%; p = 0.4) was not different. Procedural complications were more frequent in CA versus control patients (6 of 42 [14%] vs. 2 of 106 [2%]; p = 0.007); complications in CA included ventricular arrhythmias in 2 and severe bradyarrhythmias requiring pacemaker implantation in 2. The only complication in the control group was self-limited bradyarrhythmias. CONCLUSIONS: Patients with CA undergoing DCCV had a significantly high cancellation rate mainly due to a high incidence of intracardiac thrombus even among patients who received adequate anticoagulation. Although the success rate of restoring sinus rhythm was high, tachyarrhythmias and bradyarrhythmias complicating DCCV were significantly more frequent in CA patients compared with control patients.