Tricuspid regurgitation is associated with increased risk of mortality in patients with low-flow low-gradient aortic stenosis and reduced ejection fraction : results of the multicenter TOPAS study (true or pseudo-severe aortic stenosis)

Objectives : This study sought to examine the impact of tricuspid regurgitation (TR) on mortality in patients with low-flow, low-gradient (LF-LG) aortic stenosis (AS) and reduced left ventricular ejection fraction (LVEF). Background : TR is often observed in patients with LF-LG AS and low LVEF, but its impact on prognosis remains unknown. Methods : A total of 211 patients (73 ± 10 years of age; 77% men) with LF-LG AS (mean gradient <40 mm Hg and indexed aortic valve area [AVA] =0.6 cm2/m2) and reduced LVEF (=40%) were prospectively enrolled in the TOPAS (True or Pseudo-Severe Aortic Stenosis) study and 125 (59%) of them underwent aortic valve replacement (AVR) within 3 months following inclusion. The severity of AS was assessed by the projected AVA (AVAproj) at normal flow rate (250 ml/s), as previously described and validated. The severity of TR was graded according to current guidelines. Results : Among the 211 patients included in the study, 22 (10%) had no TR, 113 (54%) had mild (grade 1), 50 (24%) mild-to-moderate (grade 2), and 26 (12%) moderate-to-severe (grade 3) or severe (grade 4) TR. During a mean follow-up of 2.4 ± 2.2 years, 104 patients (49%) died. Univariable analysis showed that TR =2 was associated with increased risk of all-cause mortality (hazard ratio [HR]: 1.82, 95% confidence interval [CI]: 1.22 to 2.71; p = 0.004) and cardiovascular mortality (HR: 1.85, 95% CI: 1.20 to 2.83; p = 0.005). After adjustment for age, sex, coronary artery disease, AVAproj, LVEF, stroke volume index, right ventricular dysfunction, mitral regurgitation, and type of treatment (AVR vs. conservative), the presence of TR =2 was an independent predictor of all-cause mortality (HR: 1.88, 95% CI: 1.08 to 3.23; p = 0.02) and cardiovascular mortality (HR: 1.92, 95% CI: 1.05 to 3.51; p = 0.03). Furthermore, in patients undergoing AVR, TR =3 was an independent predictor of 30-day mortality compared with TR = 0/1 (odds ratio [OR]: 7.24, 95% CI: 1.56 to 38.2; p = 0.01) and TR = 2 (OR: 4.70, 95% CI: 1.00 to 25.90; p = 0.05). Conclusions : In patients with LF-LG AS and reduced LVEF, TR is independently associated with increased risk of cumulative all-cause mortality and cardiovascular mortality regardless of the type of treatment. In patients undergoing AVR, moderate/severe TR is associated with increased 30-day mortality. Further studies are needed to determine whether TR is a risk marker or a risk factor of mortality and whether concomitant surgical correction of TR at the time of AVR might improve outcomes for this high-risk population

Cardiac imaging for assessing low-gradient severe aortic stenosis

Up to 40% of the patients with aortic stenosis (AS) harbor discordant Doppler-echocardiographic findings, the most common discordance being the presence of a small aortic valve area (AVA ≤1.0cm2), suggesting severe AS, but a low gradient (<40mmHg), suggesting non-severe AS. The purpose of this article is to present the role of multi-modality imaging for the diagnostic and therapeutic management of this challenging entity referred as to “low-gradient” AS. Doppler-echocardiography is critical to determine the sub-type of low-gradient AS: i.e. classical low-flow, paradoxical low-flow, or normal-flow. Patients with low-flow, low-gradient (LF-LG) AS generally have a worse prognosis compared to patients with high gradient or normal-flow, low-gradient AS. Patients with low-gradient AS and evidence of severe AS benefit from aortic valve replacement (AVR). However, confirmation of the presence of severe AS is particularly challenging in these patients and requires a multi-modality imaging approach including low-dose dobutamine stress echocardiography and aortic valve calcium scoring by MDCT. Transcatheter AVR using a transfemoral approach may be superior to surgical AVR in patients with LF-LG AS. Further studies are needed to confirm the best valve replacement procedure and prosthetic valve for each category of low-gradient AS and to identify patients with low-gradient AS in whom AVR is likely to be futile

Right heart function deteriorates in breast cancer patients undergoing anthracycline-based chemotherapy

Background: Cardiotoxicity from anthracycline-based chemotherapy is an important cause of early and late morbidity and mortality in breast cancer patients. Left ventricular (LV) function is assessed for patients receiving anthracycline-based chemotherapy to identify cardiotoxicity. However, animal studies suggest that right ventricular (RV) function may be a more sensitive measure to detect LV dysfunction. The purpose of this pilot study was to determine if breast cancer patients undergoing anthracycline-based chemotherapy experience RV dysfunction. Methods: Forty-nine breast cancer patients undergoing anthracycline-based chemotherapy at the Ottawa Hospital between November 2007 and March 2013 and who had 2 echocardiograms performed at least 3 months apart were retrospectively identified. Right atrial area (RAA), right ventricular fractional area change (RV FAC) and RV longitudinal strain of the free wall (RV LSFW) were evaluated according to the American Society of Echocardiography guidelines. Results: The majority (48/49) of patients were females with an average age of 53.4 (95% CI: 50.1–56.7 years). From baseline to follow-up study, average LV ejection fraction (LVEF) decreased from 62.22 (95% CI: 59.1–65.4) to 57.4% (95% CI: 54.0–60.9) (P = 0.04). During the same time period, the mean RAA increased from 12.1 cm2 (95% CI: 11.1–13.0 cm2) to 13.8 cm2 (95% CI: 12.7–14.9 cm2) (P = 0.02), mean RV FAC decreased (P = 0.01) from 48.3% (95% CI: 44.8–51.74) to 42.1% (95% CI: 38.5–45.6%), and mean RV LSFW worsened from −16.2% (95% CI: −18.1 to −14.4%) to −13.81% (95% CI: −15.1 to −12.5%) (P = 0.04). Conclusion: This study demonstrates that breast cancer patients receiving anthracycline-based chemotherapy experience adverse effects on both right atrial size and RV function. Further studies are required to determine the impact of these adverse effects on right heart function and whether this represents an earlier marker of cardiotoxicity