Right ventricular and pulmonary vascular function indices for risk stratification of patients with pulmonary regurgitation.

BACKGROUND: We hypothesized that echocardiographic indices of right ventricular to pulmonary artery (RV-PA) coupling were comparable to cardiac magnetic resonance imaging (CMRI)-derived RV volumetric indices in predicting disease severity in chronic pulmonary regurgitation (PR). METHODS: Patients with ≥ moderate PR (2003-2015) with and without prior CMRI scans were enrolled into the study cohort and validation cohort, respectively. Endpoint was to determine the association between noninvasive RV-PA coupling indices (tricuspid annular plane systolic excursion/right ventricular systolic pressure [TAPSE/RVSP] and fractional area change [FAC]/RVSP ratio) and markers of disease severity, and compared this association to that of CMRI-derived RV volumetric indices and markers of disease severity (peak oxygen consumption [VO2 ], NT-proBNP and atrial and/or ventricular arrhythmias). RESULTS: Of the 256 patients in the study cohort (age 33 ± 6 years), 187 (73%) had tetralogy of Fallot (TOF) while 69 (27%) had valvular pulmonic stenosis (VPS). TAPSE/RVSP (r = 0.73, P < .001) and FAC/RVSP (r = 0.78, P < .001) correlated with peak VO2 . Among the CMRI-derived RV volumetric indices analyzed, only right ventricular end-systolic volume index correlated with peak VO2 (r = -0.54, P < .001) and NT-proBNP (r = 0.51, P < .001). These RV-PA coupling indices were tested in the validation cohort of 218 patients (age 37 ± 9 years). Similar to the study cohort, TAPSE/RVSP (r = 0.59, P < .001) and FAC/RVSP (r = 0.70, P < .001) correlated with peak VO2 . TAPSE/RVSP (but not FAC/RVSP) was also associated with arrhythmia occurrence in both the study cohort and validation cohorts. CONCLUSION: Noninvasive RV-PA coupling may provide complementary prognostic data in the management of chronic PR. Further studies are required to explore this clinical tool.

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.

Role of QRS Fragmentation for Risk Stratification in Adults With Tetralogy of Fallot.

Background Patients with tetralogy of Fallot ( TOF ) remain at risk for cardiovascular events despite successful repair. Some of the current risk stratification tools require advanced imaging and invasive studies, and hence are difficult to apply to routine patient care. A recent study showed that QRS fragmentation ( QRS -f) is predictive of mortality in patients with TOF. The current study aims to validate this result by assessing whether severity of QRS -f could predict all-cause mortality in a different TOF population. Methods and Results The authors reviewed the Mayo Adult Congenital Heart Disease database for patients with TOF who had ECG from 1990-2017. QRS -f was defined as notches in QRS complex in ≥2 contiguous leads on ECG , not related to bundle branch block, and classified as none, mild (≤3 leads), moderate (4 leads), or severe (≥5 leads). Of 465 patients (age 37±14 years) in the study, QRS -f was present in 161 (35%): mild (n=43, 9%), moderate (n=77, 17%), and severe (n=41, 9%). There were 55 deaths (12%) during 13.6±8.2 years of follow-up. Severity of QRS -f remained an independent predictor of all-cause mortality after adjustment for other ECG parameters, patient demographics, and atrial and ventricular arrhythmia (hazard ratio, 1.74 per class; 95% confidence interval, 1.08-2.93 [ P=0.041]). Conclusions The presence of severe QRS -f may be used as complementary data to the usual clinical indices to determine whether interventions such as invasive electrophysiology study should be performed in patients with nonsustained ventricular tachycardia or to proceed with pulmonary valve replacement in patients with severe pulmonary regurgitation with ventricular volumes below the guideline-directed threshold for intervention.