Risk for non-home discharge following surgery for ischemic mitral valve disease

Abstract

Objectives: To determine the frequency and risk factors for non-home discharge (NHD) and its association with clinical outcomes and quality of life (QOL) at 1 year following cardiac surgery in patients with ischemic mitral regurgitation (IMR).

Methods: Discharge disposition was evaluated in 552 patients enrolled in trials of severe or moderate IMR. Patient and in-hospital factors associated with NHD were identified using logistic regression. Subsequently, association of NHD with 1-year mortality, serious adverse events (SAEs), and QOL was assessed.

Results: NHD was observed in 30% (154/522) with 25% (n = 71/289) in moderate and 36% (n = 83/233) in patients with severe IMR (unadjusted P = .006), a difference not significant after including age (5-year change: adjusted odds ratio [adjOR], 1.52; 95% confidence interval [CI], 1.35-1.72; P < .001), diabetes (adjOR, 1.94; 95% CI, 1.27-2.94; P = .002), and previous heart failure (adjOR, 1.64; 95% CI, 1.06-2.52; P = .03). Odds of NHD were increased for patients with postoperative SAEs (adjOR, 1.85; 95% CI, 1.19-2.86; P = .01) but not based on type of cardiac surgery. Greater rates of death and SAEs were observed in NHD patients at 1 year: adjusted hazard ratio, 4.29 (95% CI, 2.14-8.59; P < .001) and adjusted rate ratio, 1.45 (95% CI, 1.03-2.02; P = .03), respectively. QOL did not differ significantly between groups.

Conclusions: NHD is common following surgery for IMR, influenced by older age, diabetes, previous heart failure, and postoperative SAEs. These patients may be at greater risk of death and subsequent SAEs after discharge. Discussion of NHD with patients may have important implications for decision-making and guiding expectations following cardiac surgery.

Keywords: mitral regurgitation; mitral valve disease; non-home discharge; postoperative SAE; quality of life.

Figure 1.

Consort Diagram

Figure 2.

Baseline and in-hospital factors associated with NHD Key: AE, adverse event; CI, confidence interval; NHD, non-home discharge Patient factors and intra- and post-operative factors associated with non-home discharge. The blue square represents the estimated odds ratio and the red lines extend from the lower limit to the upper limit of the estimated 95% confidence interval. The baseline model was adjusted for MR severity (moderate/severe). The in-hospital model was adjusted for age, diabetes, HF, MR severity, and procedure type (CABG alone, MV repair alone, MV replacement alone, CAGB + MV repair, CABG + MV replacement). The reference category was home discharge.

Figure 3.

Kaplan-Meier curve for all-cause mortality by index hospital disposition Key: CI, confidence interval; HR, hazard ratio Kaplan-Meier estimates of the 1-year cumulative incidence of death with 95% confidence limits stratified by index hospital discharge disposition. Hazard ratio (HR) and p-value were based on Cox proportional hazards model adjusted for age, MR severity, cardiopulmonary bypass time, baseline history of smoking, baseline history of percutaneous coronary intervention, packed red blood cells transfusion during the index surgery. Tick marks on the Kaplan-Meier curves indicate censored subjects. The number of patients at risk is represented in the table below the graph. Median observation time was 3.2 (Interquartile Range [IQR], 1.4–6.2) months for patients discharged to a non-home setting and 4.7 (IQR, 1.7–7.8) months for patients discharged home.

Figure 4.

Unadjusted serious adverse event rates at 1 year by index hospital discharge disposition Key: CI, confidence interval; SAE, serious adverse event Unadjusted serious adverse event rates for patients discharged to a non-home setting and home. The height of the bar graphs represent the unadjusted SAE rate for each group and the lines extend from the lower limit to the upper limit of the estimated 95% confidence interval. The adjusted rate ratio was based on a Poisson model with robust variance estimation and was adjusted for age, MR severity, procedure type (CABG alone, mitral valve repair alone, mitral valve replacement alone, CAGB + mitral valve repair, CABG + mitral valve replacement), baseline history of hypertension, baseline history of myocardial infarction, baseline history of stroke, baseline history of renal sufficiency, baseline history of chronic lung disease, baseline history of smoking, concomitant procedures during the index surgical procedure.

Figure 5.

Risk factors and outcomes associated with non-home discharge Key: DM, diabetes mellitus; HF, heart failure; Hx, history; MR, mitral regurgitation; MV, mitral valve; NHD, non-home discharge; SAE, serious adverse event Older age, diabetes, history of heart failure, and post-operative serious adverse events are risk factors for non-home discharge in patients with ischemic mitral regurgitation undergoing cardiac surgery. Discharge to a non-home setting is associated with higher rates of morality and serious adverse events at 1 year.