**4. Treatment of pulmonary hypertension in cardiac surgery based on pathophysiology and etiology**

The approach to pharmacological and non-pharmacological treatment of PH will be directed towards the cause or the consequence of PH, as illustrated in Fig. **5**. Most often, treatment of the underlying mechanism causing PH requires non-pharmacological approaches, while pharmacological approaches will usually be the solution for the treatment of persisting PH and its consequence, RV failure.

## **4.1 Pharmacological and non-pharmacological approaches**

Therapeutic management of PH has dramatically improved in the last years, offering both relief from symptoms and prolonged survival. However, there is still no cure for this disease. Moreover, in presence of PH, the choice of the appropriate therapy should rely on evidencebased medicine. By performing a Medline search using the keywords 'randomized controlled trial', 'humans', 'adults', 'pulmonary hypertension' and 'English', a total of 14 articles in cardiac surgery were retrieved. These publications were then classified according to their levels of evidence (Sackett, 1989; Moher et al., 2001) and summarized in Table **2**. Most of the studies reviewed were based on a small number of patients and had


CABG: coronary artery bypass graft; CO: cardiac output; CPB: cardiopulmonary bypass; iNO: inhaled nitric oxide; iPGI2: inhaled prostacyclin; MVR: mitral valve replacement; NO: nitric oxide; NTG: nitroglycerin; PAOP: pulmonary artery occlusion pressure; PGE1: prostaglandin E1; PGI2: prostacyclin; PH: pulmonary hypertension; RCT: randomized controlled trial; UK: United Kingdom; USA: United States of America.

Table 2. Randomized Controlled Trial in the Treatment of Pulmonary Hypertension in Adult Cardiac Surgery

288 Perioperative Considerations in Cardiac Surgery

Fig. 9. Patient-prosthesis aortic valve mismatch. A 71-year-old man with a body surface area of 1.89 m2 was re-operated for symptoms of severe aortic valve stenosis. He had an aortic vavle replacement (AVR) 4 years before with a Carbomedics 19 mm mechanical bileaflet prosthesis (non-indexed effective orifice area = 1.06 cm2). (**A**) The preoperative mean gradient was 41 mmHg although the intraoperative inspection of the prosthetic valve was completely normal. (**B**) Intraoperative view of an aortic root enlargement procedure in a 69 year-old patient with a reduced aortic diameter requiring AVR. Courtesy of Dr. Michel

(Magne et al., 2007) studied 929 patients who underwent mitral valve replacement (MVR), following them up to 15 years. Mitral valve PPM was defined according to the indexed valve EOA as not clinically significant (EOA > 1.2 cm²/m²), moderate (1.2 cm²/m² ≥ EOA > 0.9 cm²/m²), and severe (EOA 0.9 cm²/m²). Prevalence of moderate and severe PPM was 69% and 9%, respectively. In addition, severe PPM was found to be associated with residual PH and a 3-fold increase in postoperative mortality after adjustment for other risk factors. This relevant new finding is currently absent from the majority of studies involving

**4. Treatment of pulmonary hypertension in cardiac surgery based on** 

The approach to pharmacological and non-pharmacological treatment of PH will be directed towards the cause or the consequence of PH, as illustrated in Fig. **5**. Most often, treatment of the underlying mechanism causing PH requires non-pharmacological approaches, while pharmacological approaches will usually be the solution for the treatment of persisting PH

Therapeutic management of PH has dramatically improved in the last years, offering both relief from symptoms and prolonged survival. However, there is still no cure for this disease. Moreover, in presence of PH, the choice of the appropriate therapy should rely on evidencebased medicine. By performing a Medline search using the keywords 'randomized controlled trial', 'humans', 'adults', 'pulmonary hypertension' and 'English', a total of 14 articles in cardiac surgery were retrieved. These publications were then classified according to their levels of evidence (Sackett, 1989; Moher et al., 2001) and summarized in Table **2**. Most of the studies reviewed were based on a small number of patients and had

Carrier. With permission from Denault *et al*. (Denault et al., 2010a).

**4.1 Pharmacological and non-pharmacological approaches** 

predictors of survival in mitral valve surgery.

**pathophysiology and etiology** 

and its consequence, RV failure.

hemodynamic changes as their primary end-points. Various pharmacological agents were studied: inhaled prostacyclin I2 (iPGI2), inhaled nitric oxide (iNO), heparinase, protamine and intravenous vasodilators including prostaglandin E1 (PGE1), nitroglycerin (NTG), nitroprusside, milrinone, enoximone, dobutamine, oral sildenafil, beraprost and oxygen. Findings on pharmacological and non-pharmacological approaches for the treatment of PH in cardiac surgery will be discussed together in this section.
