Assessment and Implications of Right Ventricular Afterload in Tetralogy of Fallot.
Egbe AC, Taggart NW, Reddy YNV, Sufian M, Banala K, Vojjini R, Najam M, Osman K, Obokata M, Borlaug BA.
Am J Cardiol. 2019 Dec 1;124(11):1780-1784. doi: 10.1016/j.amjcard.2019.08.035. Epub 2019 Sep 9.
Select item 30772131
Take Home Points:
- In adult patients with repaired tetralogy of Fallot (TOF), higher right ventricle systolic pressure (RVSP) is associated with worse prognosis including a higher risk of death or transplant. However, there was no such association with right ventricle outflow tract (RVOT) obstruction severity.
- In this study, there was good correlation between invasively measured and Doppler derived RVSP.
Commentary from Dr. Maan Jokhadar (Atlanta GA), section editor of ACHD Journal Watch:
Repaired TOF patients commonly have residual RVOT obstruction and increased right ventricle (RV) pressure overload. This is in addition to the increased risk of pulmonary valve regurgitation after repair and right ventricle volume overload.
Dr. Egbe and colleagues from Mayo Clinic in Rochester, Minnesota performed a retrospective cohort analysis of 266 adult TOF patients who had contemporaneous echocardiography and cardiac catheterization (within 48 hours) between 1990 and 2015. Patients with aortopulmonary collaterals were excluded. The mean age was about 35 and the mean follow-up with just under 13 years.
In this study, invasively measured RVSP was used as an index of RV afterload, which can increase as a result of any number of factors that include RVOT obstruction, pulmonary artery vascular obstruction, pulmonary vascular resistance, and increased left heart filling pressure.
Study participants were divided into 2 groups based on RVOT gradient of less or more than 36 mmHg. About 66% (175 patients) had significant RVOT obstruction and the rest did not. During a follow-up period of almost 13 years, there was no significant mortality difference between patients with and without RVOT obstruction: 27/175 patients died in the RVOT obstruction group and 8/91 patients died in the no RVOT obstruction group.
Of the 35 patients who died, right heart failure was the cause in 14, sudden-death in 11, sepsis with multi organ system failure in 3, postoperative death in 4, major bleeding in 2, and 1 died of unknown causes. There were 4 patients who had heart transplant.
In this study, there was good correlation between invasively measured and Doppler derived RVSP.
In adult repaired TOF patients, higher RVSP, as a marker of RV afterload, was independently associated with death and heart transplant, whether assessed invasively or non-invasively. However, there was no such association with RVOT obstruction. Thus, increased RV pressure overload from any cause is a marker of worse prognosis in repaired TOF patients. Further study is needed to determine if reducing RV pressure overload improved outcomes.
The results of the study bolster the notion that elevated RVSP is helpful in the risk stratification and decision-making regarding pulmonary valve intervention for patients with repaired TOF and pulmonary regurgitation. However, further study is needed.