Left atrial strain in acute heart failure: clinical and prognostic insights

AIMS

In acute heart failure (AHF), the consequences of impaired left atrial (LA) mechanics are not well understood. We aimed to define the clinical trajectory of LA mechanics by left atrial strain (LAS) analysis.

METHODS AND RESULTS

Eighty-five consecutive AHF patients with reduced, mildly reduced, and preserved left ventricular ejection fraction (LVEF) were enrolled in the LAS-AHF trial and underwent LA mechanics analysis by speckle tracking echocardiography. Seventy-seven patients were followed-up (FU) at 6 and 12 months. At hospital admission, discharge, 6 and 12 months post-discharge, LA reservoir function (LAS), LA pump strain, LAVi, LA stiffness, indicators of right ventricular (RV) and left ventricular (LV) function, congestion indexes (B lines, inferior vena cava, X-ray congestion score index), and biomarkers (NT-pro-BNP) were measured. The primary outcome was time to first event of re-hospitalization, worsening HF, or cardiovascular death. From admission to discharge, RV function significantly improved after decongestion, whereas no significant differences were observed in LA dynamics and LV function. In sinus rhythm patients with mild or no mitral regurgitation, decongestion was associated with a significant improvement of LAS and LA pump strain rate during hospitalization. At 12 months, 24 CV events occurred and lack of LAS improvement at 12 months FU emerged as the most powerful predictor followed by NT-pro-BNP. Kaplan-Meier curves showed a better survival for LAS >16%, improvement of LAS > 5%, and an LAS/LAVi ratio >0.25%/mL/m2 compared with lower cut-off values [log-rank: heart rate (HR) 3.5, 95% confidence interval (CI) 1.8-7.3, P = 0.004; log-rank: HR 3.6, 95% CI 2-7.9, P < 0.01; log-rank: HR 3.27, 95% CI 1.4-7.7, P = 0.007].

CONCLUSION

In AHF of any LVEF, LA dynamics is highly predictive of re-hospitalization and cardiovascular outcome and allows to ease risk-stratification, potentially becoming an early reference target for improving long-term outcome.

Cardiac Damage and Conduction Disorders after Transcatheter Aortic Valve Implantation

Recently, a staging system using 4 grades has been proposed to quantify the extent of cardiac damage associated with aortic stenosis (AS), namely AS-related cardiac damage staging (ASCDS). ASCDS is independently associated with all-cause mortality and important clinical outcomes. To evaluate whether it might be associated with the occurrence of conduction system disorders after TAVI, a total of 119 symptomatic patients with severe AS who underwent a TAVI were categorized according to ASCDS: group 1 (13.5%): no or LV damage; group 2 (58.8%): left atrial/mitral valve damage, atrial fibrillation (AF); group 3 (27.7%): low-flow state, pulmonary vasculature/tricuspid valve/RV damage. After TAVI, 34% of patients exhibited LBBB and 10% high-degree atrioventricular block (HD-AVB). No patient in group 1 developed HD-AVB whereas new LBBB was frequent in groups 2 and 3. Twenty-one patients presented with paroxysmal AF with a higher rate for each group increment (group 1: n = 0, 0%; group 2: n = 11, 15.7%; group 3: n = 10, 30.3%) (p = 0.012). Patients in group 3 had the higher rate of permanent pacemaker implantation (PPMI) (group 1: n = 1, 6.3%; group 2: n = 7, 10%; group 3: n = 9, 27.3%) (p = 0.012). In conclusion, ASCDS might help identify patients at higher risk of conduction disorders and PPMI requirement after TAVI.

A new integrative approach combining right heart catheterization and echocardiography to stage aortic stenosis-related cardiac damage

Introduction

Although staging of the extent of aortic stenosis (AS)-related cardiac damages is usually performed via echocardiography, this technique has considerable limitations in assessing pulmonary artery and right chamber pressures. The present hypothesis-generating study sought to explore the efficacy of a staging system of cardiac damage based on echocardiographic and invasive [right heart catheterization (RHC)] hemodynamic parameters in patients undergoing transcatheter aortic valve implantation (TAVI).

Methods

We studied 90 symptomatic patients with severe AS in whom echocardiographic and invasive evaluation by RHC was obtained prior to TAVI. Cardiac damage stages were defined as follows: no cardiac damage (stage 0), left ventricular (LV) damage (stage 1), left atrial or mitral valve damage (stage 2), pulmonary vasculature or tricuspid valve damage (stage 3), and right ventricular (RV) dysfunction or low-flow state (stage 4). With the integrative approach using RHC, pulmonary hypertension (PH) was defined as an mPAP ≥25 mmHg and the low-flow state corresponded to a cardiac index of <1.8 L/min/m2 and a right atrial pressure of >10 mmHg.

Results

During follow-up (median: 2.9 years), 43 patients (47.8%) died. The integrative cardiac damage staging was associated with a significant increase in all-cause and cardiovascular mortality per each increase of cardiac damage stage, whereas the outcome was similar according to the echocardiographic staging.

Conclusions

A staging system of cardiac lesion based on echocardiographic and invasive hemodynamic parameters in patients with severe AS undergoing TAVI predicts mortality. Patients with pre-existing PH, ≥ moderate tricuspid regurgitation and/or RV dysfunction, and a low-flow state had a markedly increased risk of death. Further larger studies are needed to validate our findings.

The Effect of Elective Ligation of the Arteriovenous Fistula on Cardiac and Renal Functions in Kidney Transplant Recipients

Key Points

Surgical AVF ligation in KTRs is associated with a significant increase in diastolic BP while systolic BP remains stable. AVF closure in KTRs leads to an improvement of LV and LA morphology and a decrease in serum NT-proBNP levels. There is no significant effect of AVF ligation on kidney allograft function: The eGFR remains stable over time.

Background

Kidney transplantation is considered as the best kidney replacement therapy, and arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis. The systematic ligation of a functioning AVF in stable kidney transplant recipients (KTRs) remains debatable.

Methods

In this prospective study, we investigated the hemodynamic effect of the surgical closure of AVF in KTRs. Forty-three KTRs underwent an ambulatory BP monitoring before surgical closure of AVF (T0) and 12 months later (M12), as well as measurement of serum cardiac biomarkers (i.e. , soluble suppression of tumorigenicity 2, N-terminal pro b-type natriuretic peptide [NT-proBNP], and galectin-3). Serum tests were also performed 6 months after AVF closure (M6). An echocardiographic examination was performed at each time point. All serum creatinine values were collected to compare the individual eGFR slopes before versus after AVF closure. The latest measure of the AVF flow before kidney transplantation was recorded.

Results

Diastolic BP significantly rose from T0 to M12: +4.4±7.3 mm Hg (P = 0.0003) for 24h, +3.8±7.4 mm Hg (P = 0.0018) during the day, and +6.3±9.9 mm Hg (P = 0.0002) during the night, leading to an increased proportion of KTRs with European Society of Hypertension (ESH)-defined arterial hypertension after AVF ligation. No change was observed for systolic BP. NT-proBNP significantly dropped between T0 and M6 (345 [190; 553] to 230 [118; 458] pg/ml, P = 0.0001) and then remained stable from M6 to M12 while suppression of tumorigenicity 2 and galectin-3 levels did not change from T0 to M12. We observed a significant decrease in left ventricular (LV) end-diastolic volume, LV end-systolic volume, LV mass, interventricular septum diameter, left atrial volume, and tricuspid annular plane systolic excursion from T0 to M6 and then a stability from M6 to M12. LV ejection fraction and eGFR slope remained stable during the whole study. These observations remained unchanged after adjustment for AVF flow.

Conclusion

The closure of a patent AVF in KTRs is associated with elevation of diastolic BP, drop in serum NT-proBNP levels, reduction of left ventricular and atrial dimensions, and stability of eGFR slope.

Detachable Aortic Clamp for Minimally Invasive Cardiac Surgery

Since its first implementation, minimally invasive cardiac surgery has become more and more popular among surgeons. By avoiding a complete opening of the sternum, this surgery is traditionally associated with a faster recovery, less surgical pain and less postoperative bleeding and transfusions. With its growing popularity, the need for specifically designed surgical instrumentation is evident. Since 2008, the detachable-branch Glauber clamp (Cardiovision-Trytech, Tokyo, Japan) has been used to facilitate aortic cross-clamp during minimally invasive cardiac surgery, to optimize the intraoperative visualization field without the need for adjunctive incisions of the thorax. It has been specifically developed for limited single-access minimally invasive valve surgery. The clamp is introduced through the main access incision (mini-sternotomy or mini thoracotomy) by means of a specifically designed delivery system, which is subsequently removed, leaving inside the thorax only the detachable closed branches on the aorta. Since its first implementation, the clamp has been used in numerous patients at several cardiac surgery centers worldwide. Over the years, attempts have been made to improve its ergonomics and enhance its performance. The G2 detachable-branch Glauber clamp (USB Medical, Hatboro, PA, USA) occupies a smaller space inside the thorax, has a simplified gripping mechanism and comes with detachable arms that enhance versatility with up to 10 possible clamp configurations. This article describes the characteristics of detachable-branch aortic clamps and compares them to other aortic cross-clamps that are currently available for minimally invasive cardiac surgery.

Stroke volume index and transvalvular flow rate trajectories in severe aortic stenosis treated with TAVR

AIMS

The prognostic impact of flow trajectories according to stroke volume index (SVi) and transvalvular flow rate (FR) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains poorly assessed. We evaluated and compared SVi and FR prior and after TAVR for severe AS.

METHODS AND RESULTS

Patients were categorized according to SVi (<35 mL/m2) and FR (<200 mL/s). The association of pre- and post-TAVR SVi and FR with all-cause mortality up to 3 years was assessed with multivariable Cox regression models. Among 980 patients with pre-TAVR flow assessment, SVi was reduced in 41.3% and FR in 48.1%. Baseline flow status was not an independent mortality predictor [SVi: hazard ratio (HR) 1.22, 95% confidence interval (CI) 0.85-1.82, FR: HR 0.78, 95% CI 0.48-1.27]. Among 731 patients undergoing early (5 days, interquartile range 2-29) post-TAVR flow assessment, SVi recovered in 40.1% and FR in 49.0% patients with baseline low flow. Reduced FR following TAVR was an independent predictor of mortality (HR 1.67, 95% CI 1.02-2.74), whereas SVi was not (HR 0.97, 95% CI 0.53-1.78). Three-year estimated mortality in patients with recovered FR was lower than that in patients with reduced FR (13.3 vs. 37.7% vs, P = 0.003) and similar to that in patients with normal baseline FR (P = 0.317).

CONCLUSION

Baseline flow status was not an independent predictor of mid-term mortality among all-comers with severe AS undergoing TAVR. Flow recovery early after TAVR was frequent. Post-TAVR FR, but not SVi, was independently associated with mid-term all-cause mortality. By impacting flow status, AV replacement modifies the association of flow status with outcomes.

Assessing QT interval in COVID-19 patients:safety of hydroxychloroquine-azithromycin combination regimen

Background

Hydroxychloroquine (HCQ) and azithromycin (AZT) have been proposed for COVID-19 treatment. Data available in the literature reported a potential increased risk of fatal arrhythmias under these therapies. The aim of this study was to assess the effects of these drugs on QT interval and outcome in a COVID-19 population.

Method

A total of 112 consecutive COVID-19 patients were included in this analysis and were divided in 3 groups according to the receiving therapeutic regimens: 19 (17%) patients in Group 1 (no treatment), 40 (36%) in Group 2 (HCQ only), 53 (47%) in Group 3 (HCQ/AZT).

Results

A prolonged QTc interval was found in 61% of patients treated with HCQ alone or in combination with AZT, but only 4 (4%) patients showed a QTc > 500 ms. HCQ/AZT combination determined a greater increase of QTc duration compared to the other two strategies (Group 3 452 ± 26.4 vs Group 2 436.3 ± 28.4 vs Group 1 424.4 ± 24.3 ms, respectively; p < 0.001). Multivariate analysis demonstrated that HCQ/AZT combination (OR 9.02, p = 0.001) and older age (OR 1.04, p = 0.031) were independent predictors of QTc prolongation. The risk increased with age (incremental utility analysis p = 0.02). Twenty patients (18%) died, and no cardiac arrest neither arrhythmic fatalities were documented.

Conclusions

The HCQ/AZT combination therapy causes a significantly increase of QT interval compared to HCQ alone. Older patients under such regimen are at higher risk of experiencing QT prolongation. The use of such drugs may be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients as no arrhythmic fatalities occurred.

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Only the use of HCQ in combination with AZT causes a significant increase of QT interval.

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Older patients are at higher risk of prolonged QT when treated with HCQ with/without AZT.

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The use of HCQ alone or in combination with AZT might be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients.