Cardiac Damage Staging in Aortic Stenosis: A Perspective From the Cardiac Catheterization Laboratory

Combined Cardiac Damage Staging by Echocardiography and Cardiac Catheterization in Patients With Clinically Significant Aortic Stenosis

BACKGROUND

Cardiac damage (CD) staging enhances risk stratification in patients with clinically significant aortic stenosis (AS). We aimed to assess the prognostic value and reclassification rate of right heart catheterization (RHC) compared with transthoracic echocardiography (TTE) in characterising CD staging at 3-year follow-up in patients with clinically significant AS, to identify patients that would benefit from RHC for prognostic stratification, and to test the prognostic value of combined CD staging.

METHODS

An observational cohort study of 432 AS patients undergoing TTE and RHC were divided into moderate or asymptomatic severe (m/asAS) and symptomatic severe (ssAS) AS. Kaplan-Meier curves were used to compare survival. The accuracy in prognostic stratification was tested by area under the receiver operating characteristic curve analysis and Delong test.

RESULTS

In both cohorts, TTE- and RHC-derived staging systems had prognostic value, although the agreement between them appeared moderate. A higher proportion of patients were assigned to stage 2 by TTE than by RHC. Patients in TTE-derived stage 2 had a high reclassification rate, with 40%-50% presenting with right chamber involvement (stages 3-4) according to RHC. Discordant cases were significantly older, with higher prevalence of atrial fibrillation, markedly elevated N-terminal pro-B-type natriuretic peptide, and higher indexed left atrial volume, E/e', and systolic pulmonary artery pressure vs concordant cases (P < 0.05). The combined CD staging, integrating TTE and RHC, was more accurate in predicting mortality than the TTE-derived system (P < 0.05).

CONCLUSIONS

In patients with m/asAS and ssAS, the combined CD staging, derived from TTE and RHC, was more accurate in predicting mortality than TTE alone. In a subset of AS patients, the integration of RHC may significantly improve prognostic stratification.

Personalized intervention cardiology with transcatheter aortic valve replacement made possible with a non-invasive monitoring and diagnostic framework

One of the most common acute and chronic cardiovascular disease conditions is aortic stenosis, a disease in which the aortic valve is damaged and can no longer function properly. Moreover, aortic stenosis commonly exists in combination with other conditions causing so many patients suffer from the most general and fundamentally challenging condition: complex valvular, ventricular and vascular disease (C3VD). Transcatheter aortic valve replacement (TAVR) is a new less invasive intervention and is a growing alternative for patients with aortic stenosis. Although blood flow quantification is critical for accurate and early diagnosis of C3VD in both pre and post-TAVR, proper diagnostic methods are still lacking because the fluid-dynamics methods that can be used as engines of new diagnostic tools are not well developed yet. Despite remarkable advances in medical imaging, imaging on its own is not enough to quantify the blood flow effectively. Moreover, understanding of C3VD in both pre and post-TAVR and its progression has been hindered by the absence of a proper non-invasive tool for the assessment of the cardiovascular function. To enable the development of new non-invasive diagnostic methods, we developed an innovative image-based patient-specific computational fluid dynamics framework for patients with C3VD who undergo TAVR to quantify metrics of: (1) global circulatory function; (2) global cardiac function as well as (3) local cardiac fluid dynamics. This framework is based on an innovative non-invasive Doppler-based patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-solid interaction. We validated the framework against clinical cardiac catheterization and Doppler echocardiographic measurements and demonstrated its diagnostic utility by providing novel analyses and interpretations of clinical data in eleven C3VD patients in pre and post-TAVR status. Our findings position this framework as a promising new non-invasive diagnostic tool that can provide blood flow metrics while posing no risk to the patient. The diagnostic information, that the framework can provide, is vitally needed to improve clinical outcomes, to assess patient risk and to plan treatment.

Outcome of aortic stenosis according to invasive cardiac damage staging after transcatheter aortic valve replacement

BACKGROUND

In recent studies, a 5-stage cardiac damage classification in severe aortic stenosis (AS) based on echocardiographic parameters has shown to provide predictive value regarding clinical outcome. The objective of this study was to investigate the prognostic impact of a cardiac damage classification based on invasive hemodynamics in patients with AS undergoing transcatheter aortic valve replacement (TAVR).

METHODS

A total of 1400 patients with symptomatic AS and full invasive hemodynamic assessment before TAVR were included. Patients were categorized according to their cardiac damage stage into five groups that are defined as: stage 0, no cardiac damage; stage 1, left ventricular damage; stage 2, left atrial and/or mitral valve damage; stage 3, pulmonary vasculature and/or tricuspid valve damage; stage 4, right ventricular damage.

RESULTS

9.9% patients were classified as stage 0, 23.6% as stage 1, the majority of patients as stage 2 (33.5%), 23.1% as stage 3 and 10% as stage 4. One- and 4-year mortality were 10.1%/29.5% in stage 0, 16.1%/60.6% in stage 1, 17.3%/39.4% in stage 2, 22%/54.6% in stage 3, 27.1%/62.2% in stage 4 (p = 0.001/p < 0.001). The extent of cardiac damage was independently associated with increased mortality after TAVR (HR 1.16 per each increment in stage, 95% confidence interval 1.03-1.18; p = 0.018).

CONCLUSIONS

Cardiac damage staging in severe AS patients based on invasive hemodynamics appears to show strong association between the extent of cardiac damage and post-TAVR mortality. This staging classification provides predictive value and may improve risk stratification, therapy management and decision-making in patients with AS. Invasive Staging Classification of Cardiac Damage in Severe Symptomatic Aortic Stenosis has an Impact on Outcome after TAVR. (Top) Invasive staging criteria for cardiac damage in five stages using left ventricular end-diastolic pressure (LVEDP) for stage 1 (red), post-capillary wedge pressure (PCWP) for stage 2 (green), systolic pulmonary artery pressure (SPAP) for stage 3 (purple) and right atrial pressure (RAP) for stage 4 (yellow). The cake chart shows the distribution of the different stage in the whole cohort. (Bottom) Survival Analyses According to Stage of Cardiac Damage after Transcatheter Aortic Valve Replacement using Invasive Criteria. Kaplan-Meier plots comparing overall (left) and cardiovascular (right) 4-year survival showing with the more advancing stage a higher mortality rate.

The Role of Extravalvular Cardiac Damage Staging in Aortic Valve Disease Management

Current management of patients with aortic valve disease, including aortic valve stenosis (AS), aortic valve regurgitation (AR), and mixed aortic valve disease (MAVD), remains challenging. American and European guideline recommendations regarding the timing of intervention are mainly based on the assessment of disease severity (ie, grading), presence of symptoms related to aortic valve disease, left ventricular systolic dysfunction, or LV enlargement. Furthermore, the decision regarding the type of intervention (ie, surgical vs transcatheter) is primarily based on risk assessment from surgical risk scores. There is, however, less emphasis on the importance of the assessment of anatomic and functional cardiac repercussions of aortic valve disease to guide the clinical management of these patients. Recently, a novel approach has been proposed to improve the management of aortic valve disease with 2 main components for risk stratification of the disease: 1) grading the severity of aortic valve disease, and 2) staging the extent of extravalvular cardiac damage associated with aortic valve disease with the use of echocardiography. To date, this novel approach of extravalvular cardiac damage staging was proposed and validated only in the context of AS but could be extended to other valvular heart diseases, including AR and MAVD. Further studies are also needed to test the incremental value of additional imaging parameters (eg, myocardial fibrosis by magnetic resonance) as well as blood biomarkers (eg, natriuretic peptide, cardiac troponin, and others) to the existing cardiac damage staging schemes.

Extravalvular Cardiac Damage and Renal Function Following Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

BACKGROUND

In this study we sought to determine the differences in incidence of acute kidney injury (AKI) and acute kidney recovery (AKR) among patients undergoing transcatheter aortic valve implantation (TAVI), according to the degree of extravalvular cardiac damage (EVCD).

METHODS

From the Verona Valvular Heart Disease Registry, 674 symptomatic severe aortic stenosis (AS) patients were selected and retrospectively analysed. Using echocardiographic data, patients were classified based on the degree of EVCD.

RESULTS

After dichotomized analysis, patients in EVCD stage 3 or 4 reported a significantly higher rate of AKI (29.5% vs 11.2%; P < 0.001). Using a multivariate analysis model, higher EVCD stage, lower glomerular filtrate rate (GFR) at admission, and amount of contrast used were found to be independent predictors of AKI, whereas stage of cardiac damage and GFR were found to be independent predictors of AKR. For the overall population after multivariate analysis AKI was associated with a higher incidence of 12-month all-cause mortality (hazard ratio, 2.142; 95% confidence interval, 1.082-4.239; P = 0.029) with a significant impact in the advanced cardiac damage stages, but not in the early stages (P for interaction = 0.006). AKR did not reduce adverse clinical outcomes but was associated with improved renal function at 12 months.

CONCLUSIONS

Increase in EVCD stage was associated with a higher rate of AKI after TAVI. AKI had a negative impact on long-term clinical outcomes but only in patients with advanced cardiac damage. AKR did not reduce adverse clinical outcomes but was associated with improved renal function at 12 months.