Viewpoint: the ENIGMAS trial - when should we treat patients with moderate aortic stenosis?

On Left Ventricle Stroke Work Efficiency in Children with Moderate Aortic Valve Regurgitation or Moderate Aortic Valve Stenosis

The optimal timing for management of pediatric patients with moderate aortic valve disease [moderate aortic stenosis (modAS) or moderate aortic regurgitation (modAR)] remains unknown and largely unexplored. Although usually asymptomatic, the risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated moderate conditions warrants clearer risk stratification for appropriate timely intervention. In this study, we explore the use of a patient-specific mathematical model to introduce a new evaluative parameter of LV performance in patients with moderate aortic valve disease. Synthetic patient data (N = 520) representing healthy patients, and patients with modAS or modAR were first generated. Then, data from twenty-five pediatric patients were included in this study (healthy = 9; moderate AS = 8; modAR = 8). The effect of modAS or modAR on LV performance was evaluated by LV stroke work (LVSW) efficiency, a new non-invasive parameter. The results demonstrate that healthy patients possess a very high LVSW efficiency (synthetic data: 91 ± 2%, in vivo data: 92 ± 3%). However, modAS patients have a significant reduction in LVSW efficiency (synthetic data: 78 ± 2%, in vivo data: 76 ± 5%, p < 0.05), whereas modAR patients had the lowest LVSW efficiency (synthetic data: 58 ± 3%, in vivo data: 66 ± 7%; p < 0.05). This highlights that patients with moderate aortic valve disease require careful myocardial assessment, regardless of onset of clinical symptoms as their LV performance is significantly reduced. The evaluation of LVSW efficiency offers a promising avenue for future stratification of mixed aortic valve disease for optimal timing of management and intervention.

Antithrombotic treatment tailoring and risk score evaluation in elderly patients diagnosed with an acute coronary syndrome

Age is an important prognostic factor in the outcome of acute coronary syndromes (ACS). A substantial percentage of patients who experience ACS is more than 75 years old, and they represent the fastest-growing segment of the population treated in this setting. These patients present different patterns of responses to pharmacotherapy, namely, a higher ischemic and bleeding risk than do patients under 75 years of age. Our aim was to identify whether the currently available ACS ischemic and bleeding risk scores, which has been validated for the general population, may also apply to the elderly population. The second aim was to determine whether the elderly benefit more from a specific pharmacological regimen, keeping in mind the numerous molecules of antiplatelet and antithrombotic drugs, all validated in the general population. We concluded that the GRACE (Global Registry of Acute Coronary Events) risk score has been extensively validated in the elderly. However, the CRUSADE (Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA Guidelines) bleeding score has a moderate correlation with outcomes in the elderly. Until now, there have not been head-to-head scores that quantify the ischemic versus hemorrhagic risk or scores that use the same end point and timeline (e.g., ischemic death rate versus bleeding death rate at one month). We also recommend that the frailty score be considered or integrated into the current existing scores to better quantify the overall patient risk. With regard to medical treatment, based on the subgroup analysis, we identified the drugs that have the least adverse effects in the elderly while maintaining optimal efficacy.

Timing of Dynamic NT-proBNP and hs-cTnT Response to Exercise Challenge in Asymptomatic Children with Moderate Aortic Valve Regurgitation or Moderate Aortic Valve Stenosis

Patients with congenital aortic valve stenosis (AVS) can remain asymptomatic but may develop progressive and often underestimated exercise intolerance. The risk of increased left ventricular (LV) wall stress, irreversible myocardial fibrosis and sudden death in untreated patients warrants earlier intervention. The timing for curative therapy for severe AVS is clear, but optimal timing for moderate stenosis (modAS) is unknown. AVS often coexists with aortic regurgitation, which adds a volume overload to an already pressure-overloaded LV, adding an additional challenge to the estimation of disease severity. We investigated the possible value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) upon treadmill exercise challenge in children with asymptomatic modAS versus moderate regurgitation (modAR). The aim was to determine optimal timing of peak biochemical response. Blood samples were obtained at rest, and then at 20, 40 and 60 min after peak exercise comparing modAS and modAR to healthy controls. Exercise performance was equivalent in all groups, with no difference for biomarker levels at rest. The increase in NT-proBNP was significant in modAR at 40 min (99.2 ± 48.6 ng/L; p = 0.04) and 60 min into recovery (100.0 ± 53.7 ng/L; p = 0.01), but not in modAS. The increase in hs-cTnT was significant only at 60 min into recovery for modAS and modAR. NT-proBNP and hs-cTnT following exercise challenge are possible discriminant biomarkers of modAR from modAS and controls at 60 min into recovery despite comparable exercise performance. This offers a promising avenue for future stratification of aortic valve disease and optimal timing of intervention.