Cost-effectiveness of coronary artery bypass grafting plus mitral valve repair versus coronary artery bypass grafting alone for moderate ischemic mitral regurgitation

OBJECTIVE

The Cardiothoracic Surgical Trials Network reported that left ventricular reverse remodeling at 2 years did not differ between patients with moderate ischemic mitral regurgitation randomized to coronary artery bypass grafting plus mitral valve repair (n = 150) or coronary artery bypass grafting alone (n = 151). To address health resource use implications, we compared costs and quality-adjusted survival.

METHODS

We used individual patient data from the Cardiothoracic Surgical Trials Network trial on survival, hospitalizations, quality of life, and US hospitalization costs to estimate cumulative costs and quality-adjusted life years. A microsimulation model was developed to extrapolate to 10 years. Bootstrap and deterministic sensitivity analyses were performed to address uncertainty.

RESULTS

In-hospital costs were $59,745 for coronary artery bypass grafting plus mitral valve repair versus $51,326 for coronary artery bypass grafting alone (difference $8419; 95% uncertainty interval, 2259-18,757). Two-year costs were $81,263 versus $67,341 (difference 13,922 [2370 to 28,888]), and quality-adjusted life years were 1.35 versus 1.30 (difference 0.05; -0.04 to 0.14), resulting in an incremental cost-effectiveness ratio of $308,343/quality-adjusted life year for coronary artery bypass grafting plus mitral valve repair. At 10 years, its costs remained higher ($107,733 vs $88,583, difference 19,150 [-3866 to 56,826]) and quality-adjusted life years showed no difference (-0.92 to 0.87), with 5.08 versus 5.08. The likelihood that coronary artery bypass grafting plus mitral valve repair would be considered cost-effective at 10 years based on a cost-effectiveness threshold of $100K/quality-adjusted life year did not exceed 37%. Only when this procedure reduces the death rate by a relative 5% will the incremental cost-effectiveness ratio fall below $100K/quality-adjusted life year.

CONCLUSIONS

The addition of mitral valve repair to coronary artery bypass grafting for patients with moderate ischemic mitral regurgitation is unlikely to be cost-effective. Only if late mortality benefits can be demonstrated will it meet commonly used cost-effectiveness criteria.

Biatrial maze procedure versus pulmonary vein isolation for atrial fibrillation during mitral valve surgery: New analytical approaches and end points

OBJECTIVE

To use novel statistical methods for analyzing the effect of lesion set on (long-standing) persistent atrial fibrillation (AF) in the Cardiothoracic Surgical Trials Network trial of surgical ablation during mitral valve surgery (MVS).

METHODS

Two hundred sixty such patients were randomized to MVS + surgical ablation or MVS alone. Ablation was randomized between pulmonary vein isolation and biatrial maze. During 12 months postsurgery, 228 patients (88%) submitted 7949 transtelephonic monitoring (TTM) recordings, analyzed for AF, atrial flutter (AFL), or atrial tachycardia (AT). As previously reported, more ablation than MVS-alone patients were free of AF or AF/AFL at 6 and 12 months (63% vs 29%; P < .001) by 72-hour Holter monitoring, without evident difference between lesion sets (for which the trial was underpowered).

RESULTS

Estimated freedom from AF/AFL/AT on any transmission trended higher after biatrial maze than pulmonary vein isolation (odds ratio, 2.31; 95% confidence interval, 0.95-5.65; P = .07) 3 to 12 months postsurgery; estimated AF/AFL/AT load (ie, proportion of TTM strips recording AF/AFL/AT) was similar (odds ratio, 0.90; 95% confidence interval, 0.57-1.43; P = .6). Within 12 months, estimated prevalence of AF/AFL/AT by TTM was 58% after MVS alone, and 36% versus 23% after pulmonary vein isolation versus biatrial maze (P < .02).

CONCLUSIONS

Statistical modeling using TTM recordings after MVS in patients with (long-standing) persistent AF suggests that a biatrial maze is associated with lower AF/AFL/AT prevalence, but not a lower load, compared with pulmonary vein isolation. The discrepancy between AF/AFL/AT prevalence assessed at 2 time points by Holter monitoring versus weekly TTM suggests the need for a confirmatory trial, reassessment of definitions for failure after ablation, and validation of statistical methods for assessing atrial rhythms longitudinally.