Preoperative Invasive Hemodynamic Determinants of Survival Among Patients Undergoing Aortic or Mitral Valve Surgery

[Hemodynamic target variables in the intensive care unit]

Despite broad availability, extended hemodynamic monitoring is used in practice only in the minority of critical care patients. Pathophysiological reasoning suggests that systemic perfusion pressure (and thereby arterial as well as central venous pressure), cardiac stroke volume, and the systemic oxygen balance are key variables in maintaining adequate organ perfusion. In line with these assumptions, several studies support that a goal-directed optimization of these hemodynamic variables leads to a reduction in morbidity and mortality. The appropriate monitoring modality should be selected following echocardiographic evaluation of biventricular function. Ideally, high-risk patients with limited right ventricular function should be monitored with a pulmonary artery catheter. In patients with preserved right ventricular function, transpulmonary thermodilution with special consideration of extravascular lung water seems to be sufficient to guide hemodynamic therapy.

Can We Predict Failure of Mitral Valve Repair?

Objective: To identify echocardiographic and surgical risk factors for failure after mitral valve repair. Methods: We identified a total of 77 consecutive patients from our institutional mitral valve surgery database who required redo mitral valve surgery due to recurrence of mitral regurgitation after primary mitral valve repair. A control group of 138 patients who had a stable echocardiographic long-term result was included based on propensity score matching. Systematic analysis of echocardiographic parameters was performed before primary surgery; after mitral valve repair and prior to redo surgery. Risk factor analysis was performed using multivariate Cox regression model. Results: Redo surgery was associated with the presence of pulmonary hypertension ≥ 50 mmHg (p = 0.02), a mean transmitral gradient > 5 mmHg (p = 0.001), left ventricular ejection fraction ≤ 45% (p = 0.05) before surgery and mitral regurgitation ≥moderate at time of discharge (p = 0.002) in the whole cohort. Patients with functional mitral valve regurgitation had a higher tendency to undergo redo surgery if preoperative left ventricular end-diastolic diameter exceeded 65 mm (p = 0.043) and if postoperative tenting height exceeded 6 mm (p = 0.018). Low ejection fraction was not significantly associated with the need for redo mitral valve surgery in the functional subgroup. Conclusions: Recurrent mitral regurgitation is still a valuable problem and is associated with relevant perioperative mortality. Patients with severe mitral regurgitation should undergo early mitral valve repair surgery as long as systolic pulmonary artery pressure is low, left ventricular ejection fraction is preserved, and LVEED is deceeds 65 mm.

Sildenafil for Pulmonary Hypertension in the Early Postoperative Period After Mitral Valve Surgery

OBJECTIVES

The phosphodiesterase-5 inhibitor sildenafil was developed for the treatment of pulmonary hypertension. The authors investigated the efficacy and safety of sildenafil in the early postoperative period after mitral valve surgery in patients with pulmonary hypertension.

DESIGN

A double-blind, placebo-controlled randomized trial was performed.

SETTING

The trial was performed in a single tertiary referral center.

PARTICIPANTS

Fifty consecutive patients who experienced pulmonary hypertension and underwent mitral valve surgery.

INTERVENTIONS

Patients were randomly assigned to the following 2 groups: 25 patients received 20 mg sildenafil every 8 hours, and the remaining 25 patients received placebo during the same period. Hemodynamic parameters were studied by using a pulmonary artery catheter at baseline and every 6 hours up to 36 hours.

RESULTS

Patients who received sildenafil showed a decrease in mean pulmonary pressure, from 32 ± 7 mmHg at baseline to 26 ± 3 mmHg after 36 hours, whereas no change was seen in patients who received placebo (mean pulmonary pressure 34 ± 6 mmHg at baseline and 35 ± 5 mmHg after 36 h) (p < 0.001). No significant changes in systemic hemodynamic and oxygenation were observed. Patients who received sildenafil compared with those who received placebo had a median mechanical lung ventilation time of 16 (10-31) hours versus 19 (13-41) hours (p = 0.431), intensive care unit stay of 74 (44-106) hours versus 91 (66-141) hours (p = 0.410), and a total hospitalization stay of 7 (5-10) days versus 11 (7-15) days (p = 0.009).

CONCLUSIONS

The immediate postoperative administration of sildenafil after mitral valve surgery is safe. Sildenafil demonstrates a favorable decreasing effect on pulmonary vascular pressure without systemic hypotension and ventilation-perfusion mismatch.