B-type natriuretic peptide as a biochemical marker of left ventricular diastolic function: assessment in asymptomatic patients 1 year after valve replacement for aortic stenosis

Integrating hemodynamics with ventricular and valvular remodeling in aortic stenosis. A paradigm shift in therapeutic decision making

Aortic valve stenosis (AS) has traditionally been approached in hemodynamic terms. Although hemodynamics and symptoms have formed the basis of recommending interventional treatment in AS, other factors reflecting left ventricular and valvular and/or vascular remodeling are equally important for the prognosis and outcome of patients with AS. Left ventricular and valvular/vascular remodeling in AS do not consistently correlate with hemodynamic severity of AS. Those remodeling changes are reflected and can be detected by a variety of novel laboratory and imaging techniques, including biomarkers, echocardiography, cardiac magnetic resonance and gated Computer Tomography (CT) imaging. Taking all those elements into Heart Team therapeutic decision making in patients with AS, can significantly improve appropriate patient selection for interventional treatment and patient outcomes. We review this novel approach and propose a simple algorithm for decision making by the Heart Team, in patients with moderate or severe AS.

Evaluation of left ventricular diastolic function in patients operated for aortic stenosis

Background

Left ventricular diastolic dysfunction is common in patients with aortic valve stenosis (AS) and reportedly affects prognosis after surgical aortic valve replacement (SAVR). Here we investigated whether and how diastolic function (assessed following the most recent guidelines) was affected by SAVR, and whether preoperative diastolic function affected postoperative outcome. We also examined whether long-term mortality was associated with preoperative NT-proBNP and postoperative heart failure (PHF).

Methods

We performed a prospective observational study of 273 patients with AS who underwent AVR with or without concomitant coronary artery bypass surgery. Of these patients, 247 were eligible for assessment of left ventricular (LV) filling pressure. Preoperatively and at the 6-month postoperative follow-up, we measured N-terminal pro-B type natriuretic peptide (NT-proBNP) in serum and assessed diastolic function with Doppler echocardiography. PHF was diagnosed using prespecified criteria. Multivariable logistic regression was performed to explore variables associated with high LV filling pressure. Cox regression was performed to explore variables associated with mortality, accounting for timeto-event.

Results

At the time of surgery, 22% (n = 54) of patients had diastolic dysfunction expressed as high LV filling pressure. Of these 54 patients, 27 (50%) showed postoperative diastolic function improvement. Among the 193 patients with preoperative low LV filling pressure, 24 (12%) showed postoperative diastolic function deterioration. Increased long-term mortality was associated with PHF and high preoperative NT-proBNP, but not with preoperative or postoperative diastolic dysfunction. Cox regression revealed the following independent risk factors for long-term mortality: diabetes, renal dysfunction, preoperative NT-proBNP>960 ng/L, age, and male gender.

Conclusions

Surgery for aortic stenosis improved diastolic function in patients with high LV filling pressure in 50% of the patients. Our results could not confirm the previously suggested role of diastolic dysfunction as a marker for poor long-term survival after SAVR. Our findings showed that both PHF and high preoperative NT-proBNP were associated with long-term mortality.

Natriuretic peptides for the detection of diastolic dysfunction and heart failure with preserved ejection fraction-a systematic review and meta-analysis

BACKGROUND

An overview of the diagnostic performance of natriuretic peptides (NPs) for the detection of diastolic dysfunction (DD) and heart failure with preserved ejection fraction (HFpEF), in a non-acute setting, is currently lacking.

METHODS

We performed a systematic literature search in PubMed and Embase.com (May 13, 2019). Studies were included when they (1) reported diagnostic performance measures, (2) are for the detection of DD or HFpEF in a non-acute setting, (3) are compared with a control group without DD or HFpEF or with patients with heart failure with reduced ejection fraction, (4) are in a cross-sectional design. Two investigators independently assessed risk of bias of the included studies according to the QUADAS-2 checklist. Results were meta-analysed when three or more studies reported a similar diagnostic measure.

RESULTS

From 11,728 titles/abstracts, we included 51 studies. The meta-analysis indicated a reasonable diagnostic performance for both NPs for the detection of DD and HFpEF based on AUC values of approximately 0.80 (0.73-0.87; I² = 86%). For both NPs, sensitivity was lower than specificity for the detection of DD and HFpEF: approximately 65% (51-85%; I² = 95%) versus 80% (70-90%; I² = 97%), respectively. Both NPs have adequate ability to rule out DD: negative predictive value of approximately 85% (78-93%; I² = 95%). The ability of both NPs to prove DD is lower: positive predictive value of approximately 60% (30-90%; I² = 99%).

CONCLUSION

The diagnostic performance of NPs for the detection of DD and HFpEF is reasonable. However, they may be used to rule out DD or HFpEF, and not for the diagnosis of DD or HFpEF.

Prognostic Implications of Baseline B-type Natriuretic Peptide in Patients Undergoing Transcatheter Aortic Valve Implantation

B-type natriuretic peptide (BNP) levels have been shown to predict outcomes in surgical aortic valve replacement patients. BNP levels have not been well studied in patients undergoing transcatheter aortic valve implantation (TAVI). The purpose of this study is to define the utility of baseline BNP levels in predicting short-term outcomes after TAVI. In this retrospective, observational, study from 2012 to 2019, we reviewed data on 1297 low-risk, intermediate-risk and high-risk patients who underwent TAVI. Patients were dichotomized into those with baseline BNP levels above or below 500 pg/ml. Our primary outcome was a composite of inpatient stroke and death. Our secondary outcome was a composite of 30-day stroke, death and readmission. There were 975 patients with a baseline BNP level of <500 pg/ml and of those, 2% had our primary composite outcome and 13% of patients had our secondary composite outcome. There were 322 patients with a baseline BNP level of ≥500 pg/ml and of those, 6% had our primary composite outcome and 19% of patients had our secondary composite outcome. Those with a baseline BNP level ≥500 pg/ml were 3.47 times more likely (confidence of interval [CI] 1.727, 6.993, p = 0.0005) to have our primary composite outcome and were 1.72 times more likely (CI 1.186, 2.506, p = 0.0043) to have our secondary composite outcome. In conclusion, after adjustments for discrepant baseline characteristics, baseline BNP levels were independently predictive of a composite of inpatient stroke or death and a composite of 30-day stroke, death or readmission after TAVI. Those low, intermediate and high-risk patients whose baseline BNP is ≥500 pg/ml may ultimately require closer post-TAVI monitoring.

The role of mechanotransduction in heart failure pathobiology-a concise review

This review evaluates the role of mechanotransduction (MT) in heart failure (HF) pathobiology. Cardiac functional and structural modifications are regulated by biomechanical forces. Exposing cardiomyocytes and the myocardial tissue to altered biomechanical stress precipitates changes in the end-diastolic wall stress (EDWS). Thereby various interconnected biomolecular pathways, essentially mediated and orchestrated by MT, are launched and jointly contribute to adapt and remodel the myocardium. This cardiac MT-mediated feedback decisively determines the primary cardiac cellular and tissue response, the sort (concentric or eccentric) of hypertrophy/remodeling, to mechanical and/or hemodynamic alterations. Moreover, the altered EDWS affects the diastolic myocardial properties independent of the systolic function, and elevated EDWS causes diastolic dysfunction. The close interconnection between MT pathways and the cell nucleus, the genetic endowment, principally allows for the wide variety of phenotypic appearances. However, demographic, environmental features, comorbidities, and also the genetic make-up may modulate the phenotypic result. Cardiac MT takes a fundamental and superordinate position in the myocardial adaptation and remodeling processes in all HF categories and phenotypes. Therefore, the effects of MT should be integrated in all our scientific, clinical, and therapeutic considerations.

Echocardiographic determinants of LV functional improvement after transcatheter aortic valve replacement

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an established therapy in high-risk patients with severe aortic stenosis. Among patients with reduced left ventricular ejection fraction (LVEF), it is unclear which patients will derive maximal benefit from TAVR.

METHODS

Clinical and echocardiographic data of patients with severe aortic stenosis and low LVEF (≤50%) who underwent TAVR at a single institution during 2009-2013 were retrospectively analyzed. Patients were divided into 2 groups post-TAVR based on improved LV function (Group A = ΔLVEF ≥ 10%) versus persistent LV dysfunction (Group B = ΔLVEF<10%). Echocardiographic parameters were assessed for their association with LVEF change post-TAVR. Kaplan-Meier analysis was performed to generate survival estimates.

RESULTS

Of 382 patients who underwent TAVR, 60 patients had low LVEF, LV function failed to improve ≥10% in 50% of patients following the procedure (Group B). At baseline echocardiograms, Group B had higher LVEF, stroke volume (SV), SV index; and lower E, E/E', and estimated pulmonary arterial systolic pressure (PASP) compared to Group A. Higher mortality was found in Group B compared to the Group A (p = 0.003) with a significantly shorter survival (Group A = 3.3 ± 0.1 years vs Group B = 2.7 ± 0.2 years, p = 0.003). One-year event free survival was 53.3% in Group B compared to 93.3% in Group A, with a stable trend over ensuing years (5-year survival; 53.3% versus 90.0%, p = 0.003).

CONCLUSIONS

In patients undergoing TAVR with depressed LV function, those who failed to improve were more likely to have relatively higher LVEF, SV, and SVI; and lower E, E/E', and PASP at baseline. Mortality rates were found to be higher in persistent LV dysfunction group. © 2015 Wiley Periodicals, Inc.

How to relate diastolic left ventricular dysfunction to the results of stress echocardiography in aortic stenosis?

In aortic stenosis (AS), altered functional capacity may be not only a result of impaired systolic performance but likewise of diastolic left ventricular (LV) dysfunction. In asymptomatic severe AS, in borderline severe AS and in low flow, low gradient AS with reduced ejection fraction (EF), assessment of systolic and diastolic LV function should be completed by evaluation of functional capacity using low dose dobutamine stress echocardiography (SE).