Nishimura, Rick

Atrial fibrillation (AF) is the most common arrhythmia among patients with heart failure (HF), and HF is the most common cause of death for patients presenting with clinical AF. AF is frequently associated with pathological atrial myocardial dysfunction and remodeling, a triad that has been called atrial myopathy. AF can be the cause or consequence of clinical HF, and the directionality varies between individual patients and across the spectrum of HF. Although initial trials suggested no advantage for a systematic rhythm control strategy in HF with reduced ejection fraction, recent data suggest that select patients may benefit from attempts to maintain sinus rhythm with catheter ablation. Preliminary data also show a close relationship among AF, left atrial myopathy, mitral regurgitation, and HF with preserved ejection, with potential clinical benefits to catheter ablation therapy. The modern management of AF in HF also requires consideration of the degree of atrial myopathy and chronicity of AF, in addition to the pathogenesis and phenotype of the underlying left ventricular HF. In this review, we summarize the contemporary management of AF and provide practical guidance and areas in need of future investigation.

Abstract Background A patent foramen ovale (PFO) is a persistent embryonic defect in the interatrial septum. Platypnoea-orthodeoxia syndrome is characterized by positional hypoxaemia that is most commonly due to right-to-left shunting through a PFO. Dynamic right-to-left shunting through a PFO can also exacerbate positional hypoxaemia without platypnea-orthodeoxia syndrome. Case summary A 78-year-old woman with hyperthyroidism and paroxysmal atrial fibrillation (AF) presented with positional hypoxaemia exacerbated by supine positioning. Diagnostic testing revealed intermittent right-to-left shunting through a PFO triggered by worsening atrial functional tricuspid regurgitation and elevated right atrial pressures. Diuresis, rate control, and thyroidectomy initially led to resolution of positional hypoxaemia, but recurrent AF episodes triggered right-to-left shunting with recurrent desaturation. Left atrial and cavo-tricuspid isthmus ablation led to restoration of normal sinus rhythm and resolution of positional hypoxaemia without PFO closure. Discussion The clinical presentation of intermittent intracardiac right-to-left shunting can mimic decompensated heart failure with pulmonary oedema. Persistent hypoxaemia out of proportion to the degree of pulmonary oedema and minimally responsive to supplemental O2 should raise suspicion for right-to-left shunt aetiology. Positional arterial blood gases can facilitate the diagnostic evaluation of refractory hypoxaemia in cases of suspected shunting. Diagnostic imaging for PFO detection includes both transthoracic and transesophageal echocardiography with Valsalva manoeuver and agitated saline injection. Closure of a PFO for management of arterial deoxygenation syndromes should not be performed before treating other causes of arterial deoxygenation and optimizing factors that may exacerbate shunting across the PFO.

Abstract Aims Obesity is a risk factor for heart failure with preserved ejection fraction (HFpEF), particularly in women, but the mechanisms remain unclear. The present study aimed to investigate the impact of central adiposity in patients with HFpEF and explore potential sex differences. Methods and results A total of 124 women and 105 men with HFpEF underwent invasive haemodynamic exercise testing and rest echocardiography. Central obesity was defined as a waist circumference (WC) ≥88 cm for women and ≥102 cm for men. Exercise‐normalized pulmonary capillary wedge pressure (PCWP) responses were evaluated by the ratio of PCWP to workload (PCWP/W) and after normalizing to body weight (PCWL). The prevalence of central obesity (77%) exceeded that of general obesity (62%) defined by body mass index ≥30 kg/m 2 . Compared to patients without central adiposity, patients with HFpEF and central obesity displayed greater prevalence of diabetes and dyslipidaemia, higher right and left heart filling pressures and pulmonary artery pressures during exertion, and more severely reduced aerobic capacity. Associations between WC and fasting glucose, low‐density lipoprotein (LDL) cholesterol, peak workload, and pulmonary artery pressures were observed in women but not in men with HFpEF. Although increased WC was associated with elevated PCWP in both sexes, the association with PCWP/W was observed in women but not in men. The strength of correlation between PCWP/W and WC was more robust in women with HFpEF as compared to men (Meng's test p = 0.0008), and a significant sex interaction was observed in the relationship between PCWL and WC ( p for interaction = 0.02). Conclusions Central obesity is even more common than general obesity in HFpEF, and there appear to be important sexual dimorphisms in its relationships with metabolic abnormalities and haemodynamic perturbations, with greater impact in women.

AbstractBackgroundMitral transcatheter edge‐to‐edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Functional mitral regurgitation originating from atrial myopathy (A‐FMR) has been described.ObjectivesWe sought to assess the clinical, echocardiographic and hemodynamic considerations in A‐FMR patients undergoing MTEER.MethodsFrom 2014 to 2020, patients undergoing MTEER for degenerative MR (DMR), functional MR (FMR), and mixed MR were assessed. A‐FMR was defined by the presence of MR > moderate in severity; left ventricular (LV) ejection fraction (LVEF) ≥ 50%; and severe left atrial (LA) enlargement in the absence of LV dysfunction, leaflet pathology, or LV tethering. The diagnosis of A‐FMR (vs. ventricular‐FMR [V‐FMR]) was confirmed by three independent echocardiographers. Baseline characteristics, procedural outcomes as well as clinical and echocardiographic follow‐up are reported. Device success was defined as final MR grade ≤ moderate; MR reduction ≥1 grade; and final transmitral gradient <5 mmHg.Results306 patients underwent MTEER, including DMR (62%), FMR (19%), and mixed MR (19%). FMR cases included 37 (63.8%) V‐FMR and 21 (36.2%) A‐FMR. Tricuspid regurgitation (≥ moderate) was higher in A‐FMR (80.1%) compared to V‐FMR (54%) and DMR (42%). Device success did not significantly differ between A‐FMR and V‐FMR (57% vs. 73%, p = 0.34) or DMR (57% vs. 64%, p = 1.0). The A‐FMR cohort was less likely to achieve ≥3 grades of MR reduction compared to V‐FMR (19% vs. 54%, p = 0.01) and DMR (19% vs. 49.7%, p = 0.01). Patients with V‐FMR and DMR demonstrated significant reductions in mean left atrial pressure (LAP) and peak LA V‐wave, though A‐FMR did not (LAP −0.24 ± 4.9, p = 0.83; peak V‐wave −1.76 ± 9.1, p = 0.39). In follow‐up, echocardiographic and clinical outcomes were similar.ConclusionsIn patients undergoing MTEER, A‐FMR represents one‐third of FMR cases. A‐FMR demonstrates similar procedural success but blunted acute hemodynamic responses compared with DMR and V‐FMR following MTEER. Dedicated studies specifically considering A‐FMR are needed to discern the optimal therapeutic approaches.

Abstract Aims Pulmonary hypertension (PH) and pulmonary vascular disease (PVD) are common and associated with adverse outcomes in left heart disease (LHD). This study sought to characterize the pathophysiology of PVD across the spectrum of PH in LHD. Methods and results Patients with PH-LHD [mean pulmonary artery (PA) pressure &gt;20 mmHg and PA wedge pressure (PAWP) ≥15 mmHg] and controls free of PH or LHD underwent invasive haemodynamic exercise testing with simultaneous echocardiography, expired air and blood gas analysis, and lung ultrasound in a prospective study. Patients with PH-LHD were divided into isolated post-capillary PH (IpcPH) and PVD [combined post- and pre-capillary PH (CpcPH)] based upon pulmonary vascular resistance (PVR &lt;3.0 or ≥3.0 WU). As compared with controls (n = 69) and IpcPH-LHD (n = 55), participants with CpcPH-LHD (n = 40) displayed poorer left atrial function and more severe right ventricular (RV) dysfunction at rest. With exercise, patients with CpcPH-LHD displayed similar PAWP to IpcPH-LHD, but more severe RV–PA uncoupling, greater ventricular interaction, and more severe impairments in cardiac output, O2 delivery, and peak O2 consumption. Despite higher PVR, participants with CpcPH developed more severe lung congestion compared with both IpcPH-LHD and controls, which was associated lower arterial O2 tension, reduced alveolar ventilation, decreased pulmonary O2 diffusion, and greater ventilation-perfusion mismatch. Conclusions Pulmonary vascular disease in LHD is associated with a distinct pathophysiologic signature marked by greater exercise-induced lung congestion, arterial hypoxaemia, RV–PA uncoupling, ventricular interdependence, and impairment in O2 delivery, impairing aerobic capacity. Further study is required to identify novel treatments targeting the pulmonary vasculature in PH-LHD.

Aims Despite the common occurrence of coronary artery disease (CAD) and heart failure (HF) with preserved ejection fraction (HFpEF), there is limited evidence to guide revascularization. Methods and Results We investigated the long‐term outcomes of coronary artery bypass grafting (CABG) in patients with HF and significant CAD across the spectrum of ejection fraction, using a large national cohort of patients from the Veteran Affairs (VA) Medical Centers in the US. Patients with HF were stratified into groups, HFpEF, HF with mid‐range ejection fraction (HFmrEF), and HF with reduced ejection fraction (HFrEF) and compared to patients with no preoperative HF. We analysed 10 396 patients. Despite an increased hazard in the first year following revascularization, the long‐term survival (median follow‐up 6.6 years; interquartile range 3.7–10.1) of HFpEF post‐CABG was similar to controls (hazard ratio 0.85, 95% confidence interval 0.68‐1.06), but survival progressively declined with HFmrEF and HFrEF. Similar trends were seen with recurrent HF hospitalization with lower risk with baseline HFpEF (43.9 ± 6.9/100 patient‐years) compared to HFmrEF (65.9 ± 3.8/100 patient‐years) and HFrEF (93.4 ± 4.8/100 patient‐years). Although HFpEF patients had lower mortality and HF hospitalization post‐CABG compared to patients with a lower ejection fraction, they experienced the highest rates of future myocardial infarction. Conclusion Although HFpEF patients with CAD have greater short‐term risk post‐CABG, their long‐term survival is comparable to controls. However, they are at increased risk for HF hospitalizations and myocardial infarction. These data support the safety of CABG in HFpEF patients and suggest continuum of mortality risk for ischaemic HF when stratified by baseline ejection fraction before revascularization.