Minimally invasive aortic valve replacement was associated with fewer in-hospital strokes or transient ischemic attacks (TIAs) in a single-center propensity-matched study of elective surgical patients. Among 155 matched pairs, no stroke/TIA events occurred after upper hemisternotomy, compared with seven after full sternotomy. The result is an encouraging observational signal, but only seven events occurred, and the analysis does not establish that a smaller incision prevents neurological injury.
Study Design and Population
Kowalówka and colleagues reviewed 1,741 consecutive isolated aortic valve replacement procedures performed from January 2014 through December 2025 at a cardiac surgical center in Katowice, Poland. After exclusions, 1,434 patients were eligible: 156 treated with minimally invasive AVR (miniAVR) and 1,278 with conventional sternotomy. Propensity matching on 10 baseline variables produced 155 pairs.
The matched patients were approximately 66 years old, with preserved mean left ventricular ejection fraction and a mean reported EuroSCORE of 1.3. Emergency, salvage, redo, active endocarditis, and concomitant procedures were excluded. These findings therefore apply to a selected elective, first-time isolated AVR population.
Surgical Approach and Perfusion Conduct
MiniAVR used an upper J-shaped hemisternotomy extending into the third or fourth right intercostal space. Cardiopulmonary bypass (CPB) used central or peripheral cannulation according to anatomy and surgeon preference; conventional AVR used full median sternotomy with central cannulation. Del Nido cardioplegia was the most common myocardial protection strategy in both groups.
MiniAVR patients had modestly longer median CPB times despite similar cross-clamp times. Biological prostheses were more frequent with miniAVR (91.6% versus 63.9%), as was Del Nido use (90.3% versus 81.9%). These differences complicate attribution of outcomes to the access incision alone.
Minimally Invasive Aortic Valve Replacement: Key Findings
| Outcome | MiniAVR | Full sternotomy |
|---|---|---|
| In-hospital stroke/TIA | 0/155 (0.0%) | 7/155 (4.5%) |
| 30-day mortality | 1/155 (0.6%) | 4/155 (2.6%) |
| Median CPB time | 70 minutes | 64 minutes |
| Median aortic cross-clamp time | 52 minutes | 50 minutes |
| Median mechanical ventilation | 8.4 hours | 10.7 hours |
| Median hospital stay | 7 days | 7 days |
| Estimated five-year survival | 94.6% | 87.2% |
Acute renal failure occurred in 1.3% of each group. Postoperative atrial fibrillation, re-exploration for bleeding or tamponade, permanent pacemaker implantation, and ICU stay did not differ significantly. These nonsignificant findings do not demonstrate equivalence or exclude clinically relevant differences.
Interpreting Zero Neurological Events
The primary endpoint combined in-hospital ischemic stroke and TIA; it should not be read as seven disabling strokes. The observed absolute difference was 4.5 percentage points. Zero events in 155 miniAVR patients does not imply zero underlying risk: the authors’ rule-of-three approximation gives an upper 95% limit of about 1.9%.
Because conventional logistic regression cannot reliably handle a zero-event group, the investigators used Firth penalized regression. Their three-variable adjusted model associated miniAVR with lower stroke/TIA odds (odds ratio 0.052; 95% CI, 0.003–0.832) and longer CPB with higher odds (odds ratio 1.014 per minute; 95% CI, 1.001–1.028). With only seven events and 2.3 events per model variable, these estimates are exploratory.
The univariable Firth estimate had a confidence interval crossing one and P = .061, whereas the Fisher exact comparison and adjusted model were significant. This sensitivity to analytical method reinforces the uncertainty. Neither the incision nor CPB duration can be assigned a causal effect from these data.
Why the Survival Comparison Needs Caution
Kaplan–Meier estimated five-year survival favored miniAVR (94.6% versus 87.2%; log-rank P = .047), but median follow-up was substantially shorter in that group: 1.9 versus 4.3 years. Only 24 miniAVR and 64 conventional patients remained at risk at five years. The late estimate therefore depends on a small subset of earlier patients and should not be presented as a proven survival advantage.
The study also reports cumulative deaths over all available follow-up. Those counts reflect unequal observation periods and are distinct from the five-year Kaplan–Meier estimates.
Relevance for Perfusion and Heart Teams
The study highlights the interaction between surgical access, cannulation, embolic risk, and bypass duration. For perfusion teams, the findings support discussion of coordinated operative planning and careful review of neurological outcomes. They do not identify a superior cannulation route, de-airing method, cerebral monitoring strategy, or CPB management target.
Less aortic manipulation and other proposed mechanisms remain hypotheses because the study did not directly measure or isolate them. Patient anatomy, institutional experience, prosthesis choice, and the wider operative pathway remain relevant when considering miniAVR.
Limitations and Disclosures
This retrospective, single-center comparison remains vulnerable to selection bias and unmeasured confounding. Matching balanced the 10 selected variables, but peripheral vascular disease remained more common in miniAVR patients (12.3% versus 3.9%). Ascending aortic atherosclerosis, operating surgeon, and calendar year were not included in the matching model.
Only 155 of 1,278 eligible conventional patients were retained, limiting generalizability. Prosthesis and practice differences across the enrollment period may also affect outcomes. The paper analyzed matched groups as independent samples, an additional reason for caution about statistical precision. Rare neurological events, an exploratory regression model, and unequal follow-up prevent firm conclusions about neuroprotection or survival benefit.
The work received a noncommercial research grant from the Medical University of Silesia (BNW-1-101/N/6/K). The authors declare no conflicts of interest. Larger prospective multicenter studies with more events and balanced follow-up are needed.
Original Article
Kowalówka AR, Wojtczak J, Zwinczak M, Wawrzyńczak B, Jodłowski M, Gocoł R. Minimally Invasive Aortic Valve Replacement and Perioperative Stroke Risk: A Propensity-Matched Analysis. Journal of Clinical Medicine. 2026;15(20):7803. doi:10.3390/jcm15207803.
This independently written educational summary accompanies the unchanged source PDF. The cover is an AI-generated editorial illustration and is not a technical surgical or perfusion guide.
