A very rare cause of pre-capillary pulmonary hypertension: The PAMI syndrome

We report the first known case of PAMI syndrome associated with pulmonary arterial hypertension (PAH) with a positive response to cyclophosphamide and pulmonary vasodilators. The patient's history began at 7 months with severe pancytopenia and fever. As time progressed, migrating arthritis, hepatosplenomegaly, and a growth deficit manifested without a plausible explanation. At the age of 17, worsening dyspnea led to a diagnosis of severe pre-capillary pulmonary hypertension and, after a multidisciplinary evaluation, a dual therapy with both vasoactive and immunosuppressive agents led to rapid clinical improvement. After a decade of stability, stopping sildenafil caused deterioration, reversed upon reintroduction. Thirty years after the onset of signs and symptoms, a genetic test identified the underlying condition known as PAMI syndrome. As PAMI syndrome involves intense systemic inflammation similar to PAH related to systemic lupus erythematosus (SLE), parameters and functional autonomy appropriately responded to early immunosuppressive and vasoactive therapy. PAMI syndrome, a rare autoinflammatory disease, is linked to precapillary pulmonary hypertension but the exact cause and optimal treatment approach are not fully understood, requiring further research for clarification and improved treatment options.

Right Atrial Function Role in Tricuspid Regurgitation-Related Systemic Venous Congestion

Tricuspid regurgitation (TR) is a frequent valvular pathology and when significant, may cause systemic venous congestion (SC). The right atrium (RA) is an intermediate structure between the tricuspid valve and the venous system and its role in SC is not yet defined. A total of 116 patients with a measurable TR effective regurgitant orifice area (EROA) and regurgitant volume (RVol) were selected from 2020 to 2022. SC was estimated by echocardiography using inferior vena cava diameter and estimated right atrial pressure (eRAP) and by clinical congestive features. TR grade was mild in 23 patients (20%), moderate in 53 patients (46%), and severe in 40 patients (34%). There was a significant decrease in RA function measured by strain with increasing TR severity (p <0.001). There was a marked difference in RA strain between the groups with eRAP >10 and ≤10 mm Hg (25 ± 11% vs 11 ± 7%, p <0.0001). Variables independently associated with inferior vena cava diameter were RA strain (β -0.532, p <0.001), RA volume indexed (β 0.249, p = 0.002), RVol (β 0.229, p = 0.005) and EROA (β 0.185, p = 0.016), and independently associated with eRAP >10 mm Hg were EROA (odds ratio [OR] 1.024, 95% confidence interval [CI] 1.002 to 1.046), RVol (OR 1.039, 95% CI 1.007 to 1.072) and RA strain (OR 0.863, 95% CI 0.794 to 0.940). The addition of RA strain to models containing EROA or RVol significantly improved the power of the model. RA strain was independently associated with the presence of 3 or more congestive features. In conclusion, echocardiographic and clinical signs of SC are frequent in higher degrees of TR, and RA function seems to play a key role in modulating the downstream effect of TR.

1038 RIGHT VENTRICULAR-PULMONARY ARTERIAL (UN)COUPLING ESTIMATION IN PATIENTS WITH TRICUSPID REGURGITATION

Background

right-ventricular (RV)-pulmonary arterial (PA) uncoupling expressed by Tricuspid Annular Plane Systolic Excursion (TAPSE)/Pulmonary Artery Systolic Pressure (PAPs) ratio is associated with poor outcomes in patients with heart failure (HF). TAPSE/PAPs ratio has been poorly investigated in patients with tricuspid regurgitation (TR) with related volume overload and progressive right chambers remodeling.

Purpose

to assess the effectiveness of other estimation methods of RV-PA coupling in different TR severity groups compared to the classic TAPSE/PAPs ratio.

Material and Methods

116 stable patients with TR were enrolled at the time of echocardiography (43 men, 37%; mean age 74±13 years). TR severity was quantified by means of proximal isovelocity surface area (PISA) derived effective regurgitant orifice area (EROA) and regurgitant volume (RVol). RV function was assessed by RV Free Wall Longitudinal Strain (FWLS).

PAPs was obtained using the following formula: 4*(peak tricuspid regurgitation velocity)2 + right atrial pressure (RAP); meanPAP was estimated using TR continuous wave signal mean gradient (PAPmIT) and pulmonary artery regurgitation peak gradient (PAPmIP), adding RAP for both. RV-PA coupling was evaluated by TAPSE/PAPs ratio, TAPSE/PAPmIT and TAPSE/PAPmIP ratios.

Result

TR was quantified mild in 23 patients, moderate in 49, severe and torrential in 29 and 15 patients respectively. Mean RV-FWLS was -26.4±6.9% in mild, -21.8±7.4% in moderate, -18±7% and -18.3±4.2% in severe and torrential TR respectively (p&lt;0.0001).

Mean TAPSE/PAPs ratio was 0.6±0.23 mm/mmHg, 0.44±0.19, 0.38±0.19 and 0.37±0.12 mm/mmHg in mild, moderate, severe and torrential TR respectively, with a statistically significant difference between the 4 groups (p&lt;0.0001).

Mean TAPSE/PAPmIP ratio was 1.08±0.5 mm/mmHg in mild TR, 0.68±0.34 in moderate, 0.67±0.5 in severe TR and 0.47±0.13 mm/mmHg in torrential TR with a statistically significant difference between distinct TR grades (p=0.004).

Mean TAPSE/PAPmIT in mild TR was 0.92±0.5 mm/mmHg, 0.63±0.29 in moderate, 0.53±0.29 and 0.51±0.16 mm/mmHg in severe and torrential TR respectively with a statistically significant difference between the groups (p&lt;0.0001).

Finally, an analysis of covariance with RV-FWLS as potential confounder was performed: only the adjusted means of TAPSE/PAPmIP and TAPSE/PAPmIT ratios preserved a statistically significant difference between distinct TR groups (p=0.01 and p=0.019 respectively).

Conclusion

TAPSE/PAPmIP and TAPSE/PAPmIT ratios seem to preserve a stronger relation with increasing TR grade and worsening of RV disfunction, suggesting it as a more powerful index in this subset of patients. The progression of TR grade leading to a right chamber remodeling could influence the reliability of RV-PA uncoupling expressed by standard TAPSE/PAPs ratio.

897 PEAK RIGHT ATRIAL LONGITUDINAL STRAIN: A NEW PARAMETER IN PREDICTING VENOUS CONGESTION

Background

tricuspid regurgitation (TR) of either organic or functional etiology can lead to systemic venous congestion particularly in its more severe forms. Little is known about the role of the right atrium (RA) which acts as an intermediate player between TR and systemic veins.

Purpose

to assess the influence of right atrial size and function on venous congestion in TR patients.

Methods

101 stable patients with at least mild to moderate TR were enrolled at the time of echocardiography (age 74±13 years, 37% male). Systemic congestion was assessed by inferior vena cava (IVC) diameter and right atrial pressure (RAP) estimated according to inferior vena cava diameter and collapsibility. TR severity was quantified by means of proximal isovelocity surface area (PISA) derived effective regurgitant orifice area (EROA) and regurgitant volume (RVol). RA and right ventricular (RV) function were assessed respectively by peak atrial longitudinal strain (PALS) and free wall longitudinal strain (FWLS) while indexed RA volume (RAVi) by Simpson's disk summation method.

Results

TR was quantified mild or moderate in 52 patients and more than moderate in 49 patients (mean EROA 37±31 mm2; mean RVol 34±23 ml). Mean indexed RA volume was 58±31 ml/m2; mean RA strain was 18±11% and mean RV strain (free wall) was -21 ± 7%. Mean IVC diameter was 20±6 mm; estimated RAP was ≤5 mmHg in 32 patients, 6-10 mmHg in 26, 11-15 mmHg in 26 and greater than 15 mmHg in 17 patients. In univariate analysis both IVC diameter and RAP correlated significantly with EROA, RVol, RAVi and RA strain (p&lt;0.0001 for all); only RAP correlated with RV strain. In linear multivariate analysis only RAVi and RA strain were independent predictors of IVC diameter (p=0.01 and &lt;0.0001, respectively), and only RVol and RA strain were independent predictors of RAP (p=0.001 and 0.002, respectively). We found a RA strain cut-off of -15% to have a sensitivity of 82% and specificity of 70% to identify a RAP greater than 15 mmHg (area under the curve-AUC 0.842).

Conclusions

RA size and function together with the TR-related volume overload were independent predictors of venous congestion. Among these variables, only RA strain predicted both parameters of venous congestion.

740 TREATMENT STRATEGY IN CASE OF REPAIRED TRUNCUS ARTERIOSUS AND AORTIC COARCTATION

Background

Common Truncus arteriosus (TA) is a rare congenital, cyanotic heart disease with a single vessel coming out from both ventricles and related low interventricular defect, right-left shunt, low pulmonary flow and right ventricle (RV) hypertension. TA is associated with aortic coarctation (CoA) in 10-20% of cases.

Case

A 15-year-old male affected by type 2 TA and CoA undergoing first post-natal cardiac surgery with pulmonary valved conduit (PVC) implantation and CoA repair, subsequently multiple percutaneous (PC) interventions due to right pulmonary artery (RPA) stenosis and re-CoA.

He was referred to our Centre for dyspnoea on mild efforts. Echocardiography revealed RV hypertension (75% of systemic pressure) and mild disfunction. Angio-CT showed RPA re-stenosis due to peeling of previous stents, a degenerative PVC and mild residual CoA.

Results

Cardiac catheterization confirmed imaging findings, revealing the following systolic/diastolic blood pressures [mmHg]: 100/15 in RV, 33/10 in left pulmonary artery (LPA), 13/7 in RPA, 132/65 in ascending and 125/60 in descending aorta. First, extensive balloon-interrogation of stented RPA and RV outflow tract (RVOT) with semi-compliant balloon was performed followed by PC intra-stenting transluminal angioplasty of RPA with modified undersized non-compliant balloon. As RPA was very closed to CoA with risk of aortic rupture, and mostly the main pulmonary OT accounted for increased pressure gradient, RPA enlargement with re-stenting was avoided. Then, a long semi-opened-cell stent was arranged on the prosthetic RVOT and Melody valve was implanted as Valve-in-Valve (ViV), both with balloon post-dilatation. Dilated LPA with only moderate focal stenosis and mild residual CoA were excluded from intervention. Post-interventional right heart pressures were reduced: 45/4 in RVOT and 42/13 mmHg in the main PA. At 1 month dyspnoea disappeared with good effort tolerance, echocardiographic ViV mean gradient was 12 mmHg with improved RV systolic function and pressure (50% of systemic).

Conclusions

Repaired complex TA of type described may develop multiple re-stenosis of RPA. RPA optimization was not the goal of the procedure because at high risk of vessels’ injury due to the very closed anatomy with otherwise prosthetic CoA. RV pressures and dysfunction could depend on degenerative obstructive PVC. Thus, interventional approach mostly focused on the main PA aimed at working PVC could be the best effective treatment.

1000 THE EFFECT OF RIGHT VENTRICULAR SIZE AND FUNCTION ON TRICUSPID REGURGITATION SEVERITY

Background

Tricuspid regurgitation (TR) is a relatively common echocardiographic finding and its proportional influence on prognosis and quality of life has been well described. A bidirectional relationship connects TR severity and its volume overload with right ventricular (RV) dilation and dysfunction.

Purpose

to assess the impact of RV size and function on TR severity.

Material and Methods

116 stable patients with TR were enrolled at the time of echocardiography (43 men, 37%; mean age 74±13 years). TR severity was quantified by means of proximal isovelocity surface area (PISA) derived effective regurgitant orifice area (EROA) and regurgitant volume (RVol). RV size was assessed by RV End Diastolic Area (EDA) and RV function by RV Free Wall Longitudinal Strain (FWLS).

Results

TR was quantified mild in 23 patients, moderate in 53 and severe in 40 patients, with higher predominance of functional rather than organic etiology (101 vs 15 patients); median EROA was 31 mm2 and median RVol was 30 mL. Mean RV-FWLS was -25.9±7%, -21.4±7.4% and -18.4±6.4% respectively in mild, moderate and severe TR with a statistically significant difference between the groups (p=0.001). Mean RV-EDA was 19±7.7 cm2 in mild TR, 21.7±8.5 cm2 and 26.2±7 cm2 in moderate and severe TR respectively (p=0.002).

In univariate analysis both RV-FWLS and RV-EDA were predictor of TR grade estimated by TR-EROA (p=0.012 and p&lt;0.0001 respectively). In linear multivariable analysis only RV-EDA was an independent predictor of TR-EROA (p=0.001).

A ROC curve analysis confirmed the better ability of RV-EDA to identify severe TR (sTR) compared to RV-FWLS (AUC=0.738 vs AUC=0.669).

Conclusions

RV remodeling in terms of chamber dilation seems to better predict a higher TR severity compared to RV dysfunction.