Preoperative pulmonary artery hypertension as a risk factor: the tip of the iceberg

Dear Editor,

We have read the article by Velioglu et al.¹, entitled “Does pulmonary hypertension affect early-term outcomes of off-pump coronary artery bypass surgery?” with great interest. We congratulate the authors for their valuable contributions and successful off-pump coronary surgeries. However, I would like to discuss some points about preoperative pulmonary hypertension in patients scheduled to undergo off-pump coronary artery bypass graft (OPCABG) surgery.

In this current study, the authors included a total of 1,107 patients undergoing elective first-time OPCABG surgery in this retrospective observational cohort study. The patients were categorized into two groups according to their preoperative systolic pulmonary artery pressure (SPAP) values. The PHT group (n=104) consisted of patients with an SPAP value >30 mmHg, while the non-PHT group (n=1003) consisted of patients with an SPAP value ≤30 mmHg. The authors concluded that both patient groups had similar postoperative outcomes¹. Could this be due to the large number of patients with an SPAP value between 30 and 50 mmHg? How many patients with an SPAP value above 50 mmHg were in the PHT patient group? We would like to receive your valuable comments on this matter.

Chronic obstructive pulmonary disease (COPD) is an important lung disease². In these patients, PHT may develop according to the severity of obstruction and inflammation³. In this study, in which pulmonary hypertension was investigated as a risk factor, we think that the frequency of COPD is a very important parameter. In this study, the frequency of COPD was found to be 22.1% in the PHT group and 7.4% in the non-PHT group, with a p-value of 0.019¹. Considering the number of patients in the patient groups, we think that the p-value may be inaccurate with the current rates. We believe that it would be useful to check it statistically. This valuable study may be misleading, as it can be a good resource for further systematic review studies.

The European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) is an invaluable risk-scoring system in open-heart surgery operations⁴. Has EuroSCORE II been calculated for your patient groups? Could this be the reason for the similar postoperative results between the groups?

Finally, we would like to address the postoperative atrial fibrillation (PoAF) condition, which is an important problem that occurs after coronary bypass operations. The incidence of PoAF was 41.3% in the PHT group and 22.1% in the non-PHT group. The p-value is specified as 0.033. First, we think that the p-value should be recalculated because the significance seems stronger. Many factors may affect this significant difference in the frequency of PoAF between the groups. Perioperative medical treatment preferences are also important for PoAF⁵–⁷. What were your perioeprative beta-blocker statin and hypertensive treatment protocols in your patient group?

• Funding: none.

REFERENCES

• ¹
  Velioglu Y, Yuksel A, Topal D, Korkmaz UTK, Donmez I, Badem S, et al. Does pulmonary hypertension affect early-term outcomes of off-pump coronary artery bypass surgery?. Rev Assoc Med Bras (1992). 2022;68(12):1747-52. https://doi.org/10.1590/1806-9282.20220941
  » https://doi.org/10.1590/1806-9282.20220941
• ²
  Demir M, Cander B, Ayvacı BM. Evaluation of the correlation between perfusion index and prognosis in patients with chronic obstructive pulmonary disease. Eur Res J. 2022;8(1):16-23. https://doi.org/10.18621/eurj.814761
  » https://doi.org/10.18621/eurj.814761
• ³
  Joppa P, Petrasova D, Stancak B, Tkacova R. Systemic inflammation in patients with COPD and pulmonary hypertension. Chest. 2006;130(2):326-33. https://doi.org/10.1378/chest.130.2.326
  » https://doi.org/10.1378/chest.130.2.326
• ⁴
  Güvenç O, Göncü MT, Engin M, Çayır MÇ, Özyazıcıoğlu AF. Effects of coronary endarterectomy on postoperative early results in long segment coronary artery disease. Eur Res J. 2020;6(3):187-92. https://doi.org/10.18621/eurj.486547
  » https://doi.org/10.18621/eurj.486547
• ⁵
  Abanoz M, Yavuz Ş. Investigation of the effect of coronary collateral circulation quality on postoperative atrial fibrillation after coronary artery bypass graft operations in patients with right coronary artery total occlusion. Eur Res J. 2022;8(2):175-81. https://doi.org/10.18621/eurj.1056188
  » https://doi.org/10.18621/eurj.1056188
• ⁶
  Savran M, Engin M, Guvenc O, Yüksek HF, Sünbül SA, Turk T, et al. Predictive value of HATCH scoring and waist-to-height ratio in atrial fibrillation following coronary artery bypass operations performed with cardiopulmonary bypass. J Saudi Heart Assoc. 2021;33(2):117-23. https://doi.org/10.37616/2212-5043.1246
  » https://doi.org/10.37616/2212-5043.1246
• ⁷
  Aydın U, Yılmaz M, Düzyol Ç, Ata Y, Türk T, Orhan AL, et al. Efficiency of postoperative statin treatment for preventing new-onset postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting: a prospective randomized study. Anatol J Cardiol. 2015;15(6):491-5. https://doi.org/10.5152/akd.2014.5531
  » https://doi.org/10.5152/akd.2014.5531

Publication Dates

• Publication in this collection
  19 May 2023
• Date of issue
  2023

History

• Received
  13 Dec 2022
• Accepted
  10 Jan 2023