Outcomes Following Valve Replacement in Patients With Rheumatic Mitral Valve Disease With Preoperative Pulmonary Hypertension at Kenyatta National Hospital

Abstract

Background Pulmonary Hypertension (PH) complicates cardiac disease, and its presence corresponds to the severity of the disease process. PH may complicate almost any heart disorder including diseases of the mitral valve. PH is known to be a prognostic factor in surgery, particularly heart surgery where it portends increased morbidity and mortality. There is a dearth of data in Kenya and the region on the impact of PH on outcomes after MVR. Objectives To describe the association between preoperative PH with morbidity and mortality after prosthetic Mitral Valve Replacement among patients with rheumatic mitral valve disease at the Kenyatta National Hospital. Methodology Using a retrospective study model, consecutive patients who had mitral valve replacement surgery between January 2012 and December 2021 at KNH, and who had preoperative Echocardiograms were recruited. Data analysis included both descriptive and inferential analysis. Logistic regression was used to identify independent risk factors for mortality. Results of the regression model were reported in Odds ratios as well as the corresponding confidence intervals. The findings were considered significant whenever p<0.05. Results A total of 54 patients were included in the study. Majority 63% (n =34) were female. The median age was 31(IQR: 20 – 42.5) years with 51.9% (n =28) being aged ≥30 years. Most of the patients, 85.2% (n =46) had mitral regurgitation with 51.9% (n =28) of the patients classified as severe. The prevalence of pulmonary hypertension among patients undergoing MVR was 75.9% (n =41), 95%CI: 62.4% - 86.5%. Among those with PH, 51.2% (n =21) of the patients had severe disease, 26.8% (n =11) had moderate while 22% (n =9) had mild disease. Female patients(OR =10.33, 95%CI:2.37 – 45.12, p =0.002), those who had mitral stenosis (OR =6.60, 95%CI:1.70 – 25.67, p =0.012) and hospital stay (>30days)(OR =6.98, 95%CI: 1.76 – 27.63, p =0.006) were associated with increased PH. Patients who had history of alcohol use (OR =12.0, 95%CI:1.43 – 10 100.39, p =0.009), mitral stenosis(OR =23.11, 95%CI:5.01 – 106.57, p<0.001), NYHA class IIIIV (OR =8.03, 95%CI:1.61 – 40.09, p =0.011) and PH (OR= 6.98, 95%CI: 1.76 – 27.63, p =0.006) were significantly associated with longer hospital stay (>30 days). In-hospital mortality rate was 9.3%. Conclusion and recommendations The prevalence of PH in patients with mitral valve disease is high and is significantly higher in female patients, patients with mitral stenosis. Increasing PH severity is associated with longer hospital stay. The in-hospital mortality rate has also been found to be high. Thus, close monitoring of patients with Pulmonary Hypertension following MVR for the development of known complications such as acute right ventricular failure and PH crisis is crucial. This can include caring for these patients for longer periods in critical care or high-dependency units after MVR