August 21, 2026The Lancet
Multivessel coronary artery bypass grafting via small thoracotomy versus sternotomy (MIST): an investigator-initiated, international, open-label, randomised controlled trial
Key result
Minimally invasive CABG improves 1-month physical recovery vs sternotomy CABG.
- MD +2.9
- 95% CI 0.3-5.5
- P=0.031
- n=170
Why the study?
Minimally invasive cardiac surgery CABG via small thoracotomy might improve postoperative recovery compared with traditional sternotomy, but randomised evidence has been scarce.
Does MICS CABG via small thoracotomy improve patient-reported physical recovery at 1 month compared to sternotomy CABG in patients with multivessel coronary artery disease?
Key Points
- To compare patient-reported physical recovery and safety outcomes between minimally invasive cardiac surgery via small thoracotomy and standard median sternotomy for multivessel coronary artery bypass grafting.
- Investigator-initiated, international, open-label randomized controlled trial conducted across seven academic and community centers in Canada, India, China, Germany, the USA, and Japan (NCT03447938).
- A total of 170 eligible adults with angiographically confirmed multivessel coronary artery disease were randomly assigned (1:1) to minimally invasive small thoracotomy CABG (n=86) or median sternotomy CABG (n=84).
- The primary endpoint was patient-reported physical recovery at 1 month, measured by the 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS) score, analyzed by intention to treat.
- At 1 month post-surgery, SF-36 PCS scores were significantly higher in the small thoracotomy group than in the sternotomy group (mean 45.1 [SD 8.0] vs 42.2 [9.1]; mean difference 2.9 [95% CI 0.3 to 5.5]; p=0.031).
- Through 12 months of follow-up, no deaths or strokes occurred in either study arm; one major adverse cardiac or cerebrovascular event occurred in the small thoracotomy group before 1 month versus none in the sternotomy group.
Study Design
Type
RCT (n=170)
Blinding
Open-label
Randomization
1:1
Multicenter
Yes
Structured PICO
Does MICS CABG via small thoracotomy improve patient-reported physical recovery at 1 month compared to sternotomy CABG in patients with multivessel coronary artery disease?
P
Population
170 adults with multivessel coronary artery disease suitable for both surgical approaches, followed for up to 12 months.
I
Intervention
Minimally invasive cardiac surgery (MICS) coronary artery bypass grafting (CABG) via small thoracotomy
C
Comparator
Coronary artery bypass grafting (CABG) via median sternotomy
O
Outcome
Patient-reported physical recovery at 1 month, assessed by the 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS) scorepatient reported
Main Result
Mean Difference: 2.9 (95% CI 0.3–5.5)
Absolute Event Rate: 45.1% vs 42.2%
p-value: p=0.031
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“This study provides the strongest evidence to date that, in experienced hands, minimally invasive bypass surgery can help patients recover faster without compromising the long-term results patients expect.”
“The message for patients is simple: in centres with experienced teams, minimally invasive bypass surgery is a safe option that helps people return to their daily lives sooner.”
DGDr. Grant ReedInterventional Cardiologist
“The MIST trial that was just published in the Lancet showed that undergoing minimally invasive CABG had equivalent hard endpoint outcomes to a traditional sternotomy CABG. But what it also showed is what we knew, kind of, from observational studies and smaller studies, is that there's less hospital stay, less pain, less AFib (atrial fibrillation), less transfusion, and other quality of life indicators, at least in the short term, that align with the patient's preference.”
Implication
In selected patients with multivessel coronary artery disease, minimally invasive CABG via small thoracotomy significantly improves patient-reported physical recovery at 1 month compared to traditional sternotomy, with no apparent safety penalty.
Abstract
BACKGROUND Coronary artery bypass grafting (CABG) is a common but invasive operation traditionally performed through a median sternotomy. Minimally invasive cardiac surgery (MICS) CABG via small thoracotomy might improve postoperative recovery, but randomised evidence has been scarce. We aimed to compare patient-reported recovery after MICS CABG versus sternotomy CABG in patients with multivessel coronary artery disease and to describe clinical and safety outcomes. METHODS MIST was an investigator-initiated, international, open-label, randomised controlled trial done at seven centres (four academic hospitals and three community hospitals) in Canada, India, China, Germany, the USA, and Japan. Patients referred to participating surgeons for CABG were eligible if they were aged 18 years or older; had angiographically confirmed multivessel coronary artery disease, defined as lesions of at least 70% stenosis in at least two major epicardial vessels and at least two separate coronary artery territories (left anterior descending artery, left circumflex artery, or right coronary artery) or left main coronary stenosis of 50% or more; and were suitable for coronary surgery both with sternotomy CABG and MICS CABG. Patients who were haemodynamically compromised, had contraindications to either approach, had had previous cardiac surgery, or required concomitant procedures were excluded. Eligible patients were randomly assigned (1:1) to MICS CABG or sternotomy CABG by a central, web-based system, stratified by centre, with block sizes of four and six. The primary endpoint was patient-reported physical recovery at 1 month, assessed by the 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS) score. The primary analysis was by intention to treat; safety analyses were done according to treatment received. Missing 1-month questionnaire data were handled by multiple imputation. The trial was registered with ClinicalTrials.gov (NCT03447938), and is closed to recruitment. FINDINGS Between Aug 24, 2018, and Nov 26, 2024, 176 patients were enrolled, 170 of whom were randomly assigned to MICS CABG (n=86) or sternotomy CABG (n=84). The median age of patients was 67·0 years (IQR 61·0-72·0), 154 (91%) patients were male, and 16 (9%) were female. At 1 month after surgery, SF-36 PCS scores were significantly higher in the MICS CABG group than in the sternotomy CABG group (mean 45·1 [SD 8·0] vs 42·2 [9·1]; mean difference 2·9 [95% CI 0·3-5·5]; p=0·031). Clinical and safety follow-up at 1 month was complete in all patients; 12-month clinical and safety follow-up was complete in all except three patients in the sternotomy CABG group. Up to 12 months after surgery, there were no deaths or strokes in either group; one major adverse cardiac or cerebrovascular event occurred in the MICS CABG group before 1 month and none in the sternotomy CABG group. INTERPRETATION For selected patients with multivessel coronary artery disease, MICS CABG performed by experienced teams improved patient-reported physical recovery at 1 month compared with sternotomy CABG, with no apparent safety penalty through to 12 months. These findings support consideration of MICS CABG in appropriately selected patients treated by experienced teams, and further studies of implementation, recovery pathways, and long-term outcomes. FUNDING Medtronic.
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Cite This Study
Ruel et al. (2026) conducted an RCT in Multivessel coronary artery disease (n=170). Minimally invasive cardiac surgery (MICS) CABG via small thoracotomy vs. Sternotomy CABG was evaluated on Patient-reported physical recovery at 1 month, assessed by the 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS) score (MD 2.9, 95% CI 0.3-5.5, p=0.031). Minimally invasive cardiac surgery CABG improved patient-reported physical recovery at 1 month compared with sternotomy CABG (mean difference 2.9; 95% CI 0.3-5.5; p=0.031).