Aldweib N, Deghani P, Broberg CS, van Dissel A, Altibi A, Wong J, Baker D, Gindi S, Khairy P, Opotowsky AR, Shah S, Magalski A, Cramer J, Kauling RM, Dellborg M, Krieger EV, Yeung E, Roos-Hesselink J, Aboulhosn J, Nicolarsen J, Masha L, Gallego P, Celermajer DS, Kay J, Vonder Muhll I, Jameson SM, O’Donnell C, Fusco F, John AS, Macon C, Antonova P, Cotts T, Sarubbi B, Rodriguez F 3rd, DeZorzi C, Jayadeva PS, Kuo M, Kutty S, Gupta T, Burchill LJ, Rodriguez Monserrate CP, Lubert AM, Grewal J, Pylypchuk S, Belkin MN, Wilson WM.Circ Heart Fail. 2024 Sep;17(9):e011882. doi: 10.1161/CIRCHEARTFAILURE.124.011882. Epub 2024 Aug 29.PMID: 39206568
Take-home Points:
In patients with a systemic right ventricle (transposition of the great arteries, or d-TGA, post atrial switch; or congenitally corrected TGA, ccTGA), cardiac catheterization assessment findings of pulmonary capillary wedge pressure (PCWP)>20mmHg, and aortic pulsatility index <1.5 are associated with increased risk of death, transplant, mechanical circulatory support (primary outcomes) and acute decompensated heart failure (secondary outcome) in this retrospective study over a median of 11.4 yrs follow-up (interquartile range 7.5-15.9 years).
Aortic pulsatility index or API, a measure of cardiac function and filling pressures ([systolic arterial pressure- diastolic arterial pressure]/ pulmonary capillary wedge pressure) seemed to be a superior hemodynamic parameter to indicate outcomes, a value of <1.5 having an adjusted hazard ratio of 5.90 (95%CI 3.01-11.62, p<0.001) compared to those who didn’t. Patients with PCWP≥15mmHg, cardiac index <2.2l/min/m2 (called a ‘cold/wet’ profile) had an adjusted hazard ratio 3.83 (95% CI 1.63-9.02; p<0.001) of the primary and secondary outcome.
Commentary by Dr. Simon MacDonald (London, UK), section editor of ACHD Journal Watch
Introduction:
Patients with a systemic right ventricle (RV) (dTGA post atrial switch by Mustard or Senning procedure, and those with ccTGA) can develop early onset heart failure and systemic RV dysfunction. PCWP, CVP, and API seem to be predictors of adverse events in systemic left ventricular studies and thus the authors looked at these invasive hemodynamic measures in the assessment of patients with a systemic RV.
Study Design: Retrospective multicentre cohort study, conducted by the Alliance for Adult Research in Congenital Cardiology with institutional review board based at Oregon Health Science University, centers being predominantly based in North America. Catheters were performed between Jan 1994 and Dec 2020. Patients under 18 years old at time of assessment and single ventricle patients were excluded. Patients discovered to have pulmonary hypertension with normal PCWP were excluded (defined using old criteria of mPAP≥25mmHg and PCWP ≤15mmHg).
Key Finding: In patients with TGA and systemic right ventricle, hemodynamic measures of PCWP >20mmHg and API< 1.5 are significant indicators for adverse cardiac outcomes.
Further work is needed to establish treatments that can improve outcomes for these patients.
Strengths: Large multicentre study of 242 patients with comprehensive catheter hemodynamic data with a median follow-up of 11.4 years.
Limitations: It was a retrospective cohort study with sampling bias (patients who were catheterized were older, more likely to have had arrythmia, be on medical treatment than those who were not catheterized, with higher risk of death, transplant or need for mechanical support, with 242 of a total of 1721 patients having catheter data available). The authors treated dTGA and ccTGA patients as a single group (venous baffle abnormalities may confound findings in post Mustard and Senning patients). Non-invasive blood pressures appeared to be used to calculate systemic atrial pressure. The authors were not able to determine whether catheters were performed under general anesthesia, versus local/sedation, and those done with any vasopressors, and there will have been a change between 1994 and 2020 in how catheters were preformed e.g. from the arm versus femoral and neck approaches. Cardiac output was measured by either thermodilution and Fick methods, each with their own inherent errors, rather than in a standardized way. This study is in the era before the four pillars of heart failure have been established and evidence that they may be beneficial in systemic RV patients.
Discussion:
Patients with a systemic RV, the RV normally subtending a low pressure pulmonary arterial circulation, following an atrial switch repair for d-TGA (Mustard or Senning operations) or with congenitally corrected transposition (ccTGA) where the embryological RV develops in the systemic ventricular position, develop early onset heart failure and systemic RV impairment. The best assessment of these patients has been unclear, particularly regarding the best hemodynamic measures in the cath lab.
The authors here from multiple centers, part of the Alliance for Adult Research in Congenital Cardiology, combined their datasets over a 26 year period. Data was available on a sizeable number of patients, 242. Four hemodynamic profiles were studied: 1) wet/cold with PCWP≥15mmHg, CI <2.2l/min/m2; 2) wet/ warm with PCWP≥15mmHg, CI≥2.2l/min/m2; 3) dry/cold with PCWP<15mmH and CI <2.2l/min/m2; and 4) dry/warm with PCWP<15mmHg and CI≥2.2l/min/m2.
The primary outcome was first occurrence of major adverse cardiovascular events encompassing all-cause mortality, heart transplantation, or need for mechanical circulatory support. First episode of acute decompensated heart failure was a secondary outcome. In multivariate analysis, PCWP, API and mean PAP were statistically significant. PCWP>20mmHg was associated with a 3 fold increase in the primary outcome and 2-fold increase in the secondary outcome. API, combining pulse pressure and filling pressures, has been shown to predict outcomes in systemic LV failure and this would be the first large study suggesting its utility in systemic RV patients. An API <1.5 was associated with a 5 fold increase in death, transplant or MCS, illustrated in their figure 2 below, and a 3-fold increase in ADHF. A low API, with low pulse pressure and high PCWP, is in keeping with RV myocardial failure and reduced efficiency. CVP did not seem associated with adverse outcome, perhaps with a subpulmonic LV being better adapted to deal with increased afterload, nor cardiac index in this setting.
The wet/cold hemodynamic profile was linked to the highest risk of adverse outcome, consistent with PCWP being a better predictor of outcome than cardiac index, as also described in systemic LV patients, with poorest long-term survival.
Conclusion: Hemodynamic assessment of systemic right ventricular function in dTGA patients post atrial switch and in ccTGA patients revealing a low API of <1.5 and cold/wet profile of PCWP>15mmHg and CI<2.2l/min/m2 is associated with increased risk of all-cause death, heart transplant or need for mechanical circulatory support. API may be a useful prognostic hemodynamic measure in these patients.
