Coronary artery bypass grafting (CABG) remains a widely used revascularisation strategy for patients with significant coronary artery disease, traditionally performed through a median sternotomy. Minimally invasive approaches, including MICS CABG via a small thoracotomy, aim to reduce surgical trauma and accelerate recovery. Randomised evidence comparing MICS CABG with conventional sternotomy CABG for patients with multivessel disease has been limited. The MIST trial was designed to compare patient-reported physical recovery at 1 month after surgery between MICS CABG and sternotomy CABG, and to describe clinical and safety outcomes through 12 months.
MIST was an investigator-initiated, international, open-label, randomised controlled trial conducted at seven centres (four academic and three community hospitals) across Canada, India, China, Germany, the USA, and Japan. The trial recruited patients referred to participating surgeons for CABG between Aug 24, 2018, and Nov 26, 2024. Eligible patients were randomly assigned 1:1 to MICS CABG or sternotomy CABG via a central web-based system, with stratification by centre and block sizes of four and six. The trial was open label; masking of patients or surgeons is not stated in the abstract.
Inclusion criteria required adults (≥18 years) with angiographically confirmed multivessel coronary artery disease, defined as at least 70% stenosis in two or more major epicardial vessels affecting at least two separate coronary territories (left anterior descending, left circumflex, or right coronary artery), or left main stenosis of 50% or more. Patients had to be suitable candidates for coronary surgery by either surgical approach. Exclusion criteria included haemodynamic compromise, contraindications to either surgical approach, prior cardiac surgery, or the need for concomitant procedures. The trial enrolled 176 patients; 170 were randomized (86 to MICS CABG and 84 to sternotomy CABG).
Randomisation was central and web-based, stratified by centre with prespecified block sizes. The trial is described as open-label; specific masking procedures for outcome assessment are not reported in the abstract. The primary analysis was performed on an intention-to-treat basis. Safety analyses were conducted according to treatment actually received.
The prespecified primary endpoint was patient-reported physical recovery at 1 month after surgery, measured using the 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS) score. Missing 1-month questionnaire data were handled by multiple imputation. The abstract reports mean scores, standard deviations, mean differences with 95% confidence intervals, and a p value for the primary comparison. Further statistical details, including sample size calculations, adjustment covariates, or prespecified subgroup analyses, are not provided in the abstract.
Between August 2018 and November 2024, 176 patients were enrolled and 170 randomized. The median age of randomized participants was 67.0 years (IQR 61.0–72.0). The cohort was predominantly male (154 of 170, 91%) and included 16 female participants (9%). The allocation was 86 to MICS CABG and 84 to sternotomy CABG. The abstract does not provide a detailed table of baseline comorbidities or lesion distribution beyond the inclusion definitions.
At 1 month after surgery, the mean SF-36 PCS score was higher in the MICS CABG group than in the sternotomy CABG group: 45.1 (SD 8.0) versus 42.2 (SD 9.1). The mean difference was 2.9 points (95% CI 0.3–5.5), with a reported p value of 0.031, favouring MICS CABG for patient-reported physical recovery at 1 month. The primary analysis used intention-to-treat principles and addressed missing questionnaire data by multiple imputation.
Clinical and safety follow-up at 1 month was complete for all randomized patients. Twelve-month follow-up was complete for all except three patients in the sternotomy CABG group. Through 12 months, there were no deaths or strokes reported in either group. One major adverse cardiac or cerebrovascular event occurred in the MICS CABG group before 1 month; none occurred in the sternotomy group in that period. The abstract does not provide further event rates, graft patency data, reinterventions, or detailed perioperative complication rates.
In this selected patient population and when performed by experienced teams, MICS CABG via a small thoracotomy produced a statistically significant improvement in patient-reported physical recovery at 1 month compared with sternotomy CABG, without an apparent safety penalty up to 12 months. The authors suggest these findings support consideration of MICS CABG for appropriately selected patients and call for further studies addressing implementation, structured recovery pathways, and longer-term outcomes. The abstract stops mid-sentence in the final line of the interpretation in the source, and further details of proposed next steps or limitations are not reported in the abstract.
The trial was registered on ClinicalTrials.gov (NCT03447938) and is closed to recruitment. The source abstract provides primary and 12-month safety outcome summaries; more granular data, subgroup analyses, operative details, and longer-term follow-up beyond 12 months would require consultation of the full published article.