Coronary artery disease (CAD) continues to be a leading cause of morbidity and mortality worldwide, necessitating surgical revascularization in patients with multi-vessel involvement or those unsuitable for percutaneous interventions. Coronary artery bypass grafting (CABG) remains the gold standard for achieving complete and durable revascularization.

Over the past two decades, the evolution of surgical techniques has led to the emergence of minimally invasive coronary artery bypass grafting (MICS-CABG), which avoids median sternotomy and reduces surgical trauma [1]. Comparative studies have shown that MICS techniques are associated with better economic outcomes, faster recovery, and enhanced patient satisfaction [1, 2]. A growing body of evidence has highlighted the potential of MICS to improve not only clinical endpoints but also patient-reported outcomes, including physical functioning and health-related quality of life [2, 3].

Minimally invasive approaches, such as minimally invasive direct coronary artery bypass (MIDCAB), have demonstrated comparable clinical efficacy to traditional CABG while significantly reducing postoperative pain, hospital stay, and complications [3, 4]. Several investigations have underscored the benefits of MICS in promoting psychological well-being and patient coping mechanisms, particularly during the recovery period [5]. Furthermore, in settings with high surgical volumes and institutional experience, MICS has been shown to yield lower complication rates and reduced healthcare burden [6].

Despite these advantages, widespread adoption of MICS-CABG has been limited by technical challenges, training requirements, and concerns regarding graft patency and long-term outcomes. Therefore, further evaluation of its comparative effectiveness in routine clinical practice is essential. This study aims to compare clinical outcomes and quality of life in patients undergoing MICS-CABG versus conventional CABG using evidence-based metrics and patient-centered endpoints.

Aims and Objectives

The primary objective of this study was to compare clinical outcomes and health-related quality of life in patients undergoing minimally invasive coronary artery bypass grafting (MICS-CABG) versus conventional CABG. We aimed to evaluate differences in postoperative recovery parameters, including intensive care unit (ICU) stay, total hospital stay, pain perception, return to normal activity, and complication rates.

In addition, the study assessed patient-reported quality of life at 6 months using the Short Form-36 (SF-36) questionnaire, with specific attention to the physical and mental health domains. The overarching goal was to determine whether MICS-CABG offers measurable advantages over conventional CABG in a real-world clinical setting.

This was a prospective comparative study conducted at SMS Medical College, Jaipur, from March 2022 to February 2024. The study was designed to evaluate and compare clinical outcomes and quality of life in patients undergoing minimally invasive coronary artery bypass grafting (MICS-CABG) versus conventional CABG. Ethical approval was obtained from the institutional review board, and informed consent was taken from all participants.

A total of 130 patients undergoing elective CABG were enrolled in the study. Patients were assigned into two groups: those undergoing MICS-CABG (n = 65) and those undergoing conventional CABG (n = 65). Inclusion criteria included patients aged 40–75 years with multi-vessel coronary artery disease, suitable anatomy for both surgical approaches, and no history of previous cardiac surgery. Patients requiring emergency revascularization, those with significant valvular disease, or those with contraindications to either approach were excluded.

All surgeries were performed by experienced cardiothoracic surgeons with proficiency in both conventional and minimally invasive techniques. MICS-CABG was performed via a left anterior small thoracotomy without sternotomy, primarily off-pump, while conventional CABG was performed via median sternotomy, with cardiopulmonary bypass used in the majority of cases.

Baseline demographics, comorbidities, and intraoperative data were collected.

Postoperative outcomes included ICU and hospital stay, pain scores using the visual analog scale (VAS) at 48 hours, and postoperative infection. Major adverse cardiac events (MACE) were tracked at 6 months post-surgery. Quality of life was assessed at 6 months using the SF-36 questionnaire, including both physical and mental health domain scores.

Data were analyzed using standard statistical software. Continuous variables were presented as mean ± standard deviation and compared using independent t-tests. Categorical variables were expressed as frequencies and percentages and compared using chi-square or Fisher’s exact test, as appropriate. Statistical significance was defined as a p-value of less than 0.05.

Baseline Characteristics

A total of 130 patients were included in the study, with 65 undergoing minimally invasive coronary artery bypass grafting (MICS-CABG) and 65 undergoing conventional CABG. The two groups were broadly comparable across most baseline variables, although minor differences were observed in a few parameters.

The mean age of patients in the MICS-CABG group was slightly lower than in the conventional group (59.7 ± 7.8 vs. 62.8 ± 7.7 years; p = 0.022), indicating a statistically significant difference. The mean body mass index (BMI) was similar between groups (26.6 ± 2.6 vs. 27.5 ± 3.2; p = 0.079).Males predominated in both groups, comprising 78.5% in the MICS group and 75.4% in the conventional group (p = 0.835). The prevalence of diabetes was higher in the MICS group (44.6%) compared to the conventional group (29.2%), though this difference did not reach statistical significance (p = 0.102). Similarly, hypertension was observed in 40.0% of MICS patients and 56.9% of conventional CABG patients (p = 0.079), and this difference approached but did not achieve significance. Overall, the baseline clinical and demographic characteristics were sufficiently balanced between the two groups to allow for meaningful comparison of surgical and post-operative outcomes.

Table 1. Baseline Characteristics of Study Participants (MICS-CABG, n = 65; Conventional CABG, n = 65)

Data are presented as mean ± standard deviation or number (percentage). Statistical significance tested using independent t-test for continuous variables and chi-square test for categorical variables.

Intraoperative Parameters

Significant differences were observed between the two groups in key intraoperative metrics, reflecting the distinct surgical approaches. The mean number of grafts performed was significantly lower in the MICS-CABG group compared to the conventional CABG group (2.65 ± 0.37 vs. 3.17 ± 0.48; p < 0.001), consistent with the more targeted revascularization strategy typically employed in minimally invasive procedures. Cardiopulmonary bypass (CPB) use differed substantially between the groups. While 93.8% of patients in the conventional group underwent on-pump surgery, only 23.1% of MICS-CABG patients required CPB (p < 0.001), underscoring the off-pump nature of most minimally invasive approaches. Operative time was significantly shorter in the MICS group (182.1 ± 28.1 minutes) compared to the conventional group (219.9 ± 28.9 minutes; p < 0.001), as visualized in Figure 1.

Table 2. Intraoperative Parameters (MICS-CABG, n = 65; Conventional CABG, n = 65)

                 Data are presented as mean ± standard deviation or number (percentage).

(A) Percentage of patients undergoing on-pump cardiopulmonary bypass (CPB) use, showing significantly lower usage in the MICS-CABG group (23.1%) compared to the conventional group (93.8%).
(B) Boxplot showing number of grafts per patient. The conventional CABG group had a higher mean graft count (3.17 ± 0.48) than the MICS group (2.65 ± 0.37), p < 0.001.
(C) Boxplot of operative time in minutes, illustrating significantly shorter surgery duration in MICS-CABG patients (182.1 ± 28.1 min) versus conventional CABG (219.9 ± 28.9 min), p < 0.001.

Data represent group comparisons with statistical significance derived from chi-square and independent t-tests as appropriate.

Postoperative Clinical Outcomes

Significant differences were observed in early postoperative recovery metrics between the two groups.
Patients in the MICS-CABG group had a significantly shorter ICU stay compared to those in the conventional CABG group (1.9 ± 0.6 vs. 3.0 ± 0.9 days; p < 0.001). Similarly, hospital stay duration was significantly reduced in the MICS group (5.9 ± 1.1 vs. 8.7 ± 1.5 days; p < 0.001).
Pain, measured by the visual analog scale (VAS), was significantly lower in the MICS-CABG group (3.0 ± 1.0) than in the conventional CABG group (5.7 ± 1.3; p < 0.001).
Postoperative infection rates were substantially lower in the MICS group (4.6%) compared to the conventional group (23.1%; p = 0.005). There was no statistically significant difference in the incidence of major adverse cardiac events (MACE) at six months post-surgery between the two groups (1.5% vs. 3.1%; p = 1.000).
These findings highlight the advantages of minimally invasive techniques in promoting faster recovery and reducing early postoperative complications.

Table 2. Postoperative Clinical Outcomes (MICS-CABG, n = 65; Conventional CABG, n = 65)

(A) Boxplot of ICU stay duration shows significantly shorter stay in MICS-CABG patients (1.9 ± 0.6 days) compared to conventional CABG (3.0 ± 0.9 days), p < 0.001.
(B) Hospital stay was also shorter in the MICS group (5.9 ± 1.1 days) versus the conventional group (8.7 ± 1.5 days), p < 0.001.
(C) Pain scores measured using the visual analog scale (VAS) were significantly lower in MICS-CABG patients (3.0 ± 1.0) than in conventional CABG patients (5.7 ± 1.3), p < 0.001.
(D) Bar chart comparing rates of postoperative infection and major adverse cardiac events (MACE). MICS-CABG showed a lower infection rate (4.6% vs. 23.1%, p = 0.005), with similar rates of MACE at 6 months (1.5% vs. 3.1%, p = 1.000).

Statistical comparisons made using independent t-tests for continuous variables and chi-square tests for categorical outcomes.

Functional Recovery

Patients in the MICS-CABG group demonstrated significantly faster functional recovery compared to those in the conventional CABG group.

The average time to return to normal activity or work was 28.2 ± 4.4 days in the MICS group, significantly shorter than 45.2 ± 6.3 days in the conventional group (p < 0.001).

Readmission within 30 days occurred in 4.6% of MICS-CABG patients versus 10.8% in the conventional group, but this difference was not statistically significant (p = 0.323).

Table 3. Functional Recovery (MICS-CABG, n = 65; Conventional CABG, n = 65)

(A) Time to return to normal activity or work was significantly shorter in the MICS-CABG group (28.2 ± 4.4 days) compared to the conventional group (45.2 ± 6.3 days), p < 0.001.
(B) Readmission within 30 days occurred in 4.6% of MICS-CABG patients and 10.8% of conventional CABG patients, though the difference was not statistically significant (p = 0.323).

Statistical comparisons made using independent t-tests for continuous variables and chi-square tests for categorical outcomes.

Quality of Life Outcomes

At six months post-surgery, patients in the MICS-CABG group reported significantly higher quality of life scores compared to those in the conventional CABG group.
The mean SF-36 Physical Health score was 78.1 ± 5.8 in the MICS group versus 68.9 ± 7.7 in the conventional group (p < 0.001). Similarly, the SF-36 Mental Health score was higher in the MICS group (79.7 ± 6.1) compared to the conventional group (73.6 ± 5.8; p < 0.001).
These findings suggest that patients undergoing minimally invasive CABG experience a superior perceived quality of life in both physical and mental domains during recovery.

Table 4. Quality of Life Outcomes (MICS-CABG, n = 65; Conventional CABG, n = 65)

Figure 4. Quality of Life Outcomes at 6 Months Post-Surgery

(A) SF-36 Physical Health scores were significantly higher in the MICS-CABG group (78.1 ± 5.8) than in the conventional CABG group (68.9 ± 7.7), p < 0.001.
(B) SF-36 Mental Health scores were also significantly better among MICS-CABG patients (79.7 ± 6.1) compared to conventional CABG patients (73.6 ± 5.8), p < 0.001.

Scores range from 0 to 100, with higher values indicating better perceived health. Comparisons made using independent t-tests.

This comparative study demonstrates that minimally invasive coronary artery bypass grafting (MICS-CABG) offers clear advantages over conventional CABG in terms of postoperative recovery, patient-reported quality of life, and healthcare resource utilization. These findings align with multiple published reports supporting the clinical and psychosocial benefits of minimally invasive approaches [7–17]. Baseline characteristics were largely comparable between the two groups, with a slightly younger mean age in the MICS-CABG group. This minor difference may reflect patient selection trends favoring less invasive surgery in younger or lower-risk patients, as noted in earlier observational analyses [11, 17]. Significant differences were noted in intraoperative characteristics. The mean number of grafts was lower in the MICS group (2.65 ± 0.37) compared to the conventional group (3.17 ± 0.48, p < 0.001), reflecting the targeted revascularization typical of MICS. CPB use was markedly reduced in MICS-CABG (23.1% vs. 93.8%, p < 0.001), supporting its minimally invasive profile. Operative time was also significantly shorter in the MICS group (182.1 ± 28.1 min vs. 219.9 ± 28.9 min, p < 0.001). These intraoperative benefits have been previously observed in both robotic-assisted and direct minimally invasive techniques [10, 15, 17].

Postoperative outcomes favored the MICS approach. ICU stay was significantly shorter in the MICS group (1.9 ± 0.6 vs. 3.0 ± 0.9 days, p < 0.001), as was hospital stay (5.9 ± 1.1 vs. 8.7 ± 1.5 days, p < 0.001). Pain scores were notably reduced in MICS patients (3.0 ± 1.0 vs. 5.7 ± 1.3, p < 0.001). Postoperative infection rates were significantly lower in the MICS group (4.6% vs. 23.1%, p = 0.005), while MACE incidence remained low and comparable between groups (1.5% vs. 3.1%, p = 1.000). These findings reinforce earlier data showing better early recovery profiles in minimally invasive CABG [7, 9, 12, 14, 16].

Functional recovery was also improved in the MICS cohort, with significantly faster return to normal activity (28.2 ± 4.4 vs. 45.2 ± 6.3 days, p < 0.001). Although 30-day readmission rates were lower in the MICS group (4.6% vs. 10.8%), the difference did not reach statistical significance (p = 0.323). This suggests potential benefits in outpatient recovery, as supported by earlier multi-institutional and cost-benefit analyses [11, 13]. Quality of life at six months postoperatively was significantly better in the MICS group. SF-36 Physical Health scores were higher in the MICS cohort (78.1 ± 5.8 vs. 68.9 ± 7.7, p < 0.001), as were Mental Health scores (79.7 ± 6.1 vs. 73.6 ± 5.8, p < 0.001). These findings echo prior research showing enhanced quality of life with minimally invasive and off-pump techniques [8, 10, 13, 15]. The evidence suggests that surgical invasiveness correlates with recovery burden and long-term patient perception of health status.

This study provides compelling evidence that minimally invasive coronary artery bypass grafting (MICS-CABG) is associated with significantly improved short-term clinical outcomes and enhanced quality of life compared to conventional CABG. Patients undergoing MICS-CABG experienced shorter ICU and hospital stays, lower postoperative pain, and faster return to normal activity. Importantly, these benefits were achieved without compromising safety, as reflected by comparable rates of major adverse cardiac events. Furthermore, MICS-CABG demonstrated superior physical and mental quality of life outcomes at six months, reinforcing its role as a patient-centered alternative to traditional approaches.

1. Poston, R. S., Tran, R., Collins, M., Reynolds, M., Connerney, I., Reicher, B., ... & Bartlett, S. T. (2008). Comparison of economic and patient outcomes with minimally invasive versus traditional off-pump coronary artery bypass grafting techniques. Annals of surgery, 248(4), 638-646.
2. Claessens, J., Rottiers, R., Vandenbrande, J., Gruyters, I., Yilmaz, A., Kaya, A., & Stessel, B. (2023). Quality of life in patients undergoing minimally invasive cardiac surgery: a systematic review. Indian Journal of Thoracic and Cardiovascular Surgery, 39(4), 367-380.
3. Al‐Ruzzeh, S., Mazrani, W., Wray, J., Modine, T., Nakamura, K., George, S., ... & Amrani, M. (2004). The clinical outcome and quality of life following minimally invasive direct coronary artery bypass surgery. Journal of cardiac surgery, 19(1), 12-16.
4. Diegeler, A., Walther, T., Metz, S., Falk, V., Krakor, R., Autschbach, R., & Mohr, F. W. (1999, December). Comparison of MIDCAB versus conventional CABG surgery regarding pain and quality of life. In The heart surgery forum (Vol. 2, No. 4, pp. E290-E296).
5. Wray, J., Al-Ruzzeh, S., Mazrani, W., Nakamura, K., George, S., Ilsley, C., & Amrani, M. (2004). Quality of life and coping following minimally invasive direct coronary artery bypass (MIDCAB) surgery. Quality of Life Research, 13, 915-924.
6. Baishya, J., George, A., Krishnamoorthy, J., Muniraju, G., & Chakravarthy, M. (2017). Minimally invasive compared to conventional approach for coronary artery bypass grafting improves outcome. Annals of Cardiac Anaesthesia, 20(1), 57-60.
7. Anastasiadis, K., Antonitsis, P., Kostarellou, G., Kleontas, A., Deliopoulos, A., Grosomanidis, V., & Argiriadou, H. (2016). Minimally invasive extracorporeal circulation improves quality of life after coronary artery bypass grafting. European Journal of Cardio-Thoracic Surgery, 50(6), 1196-1203.
8. Biglioli, P., Antona, C., Alamanni, F., Parolari, A., Toscano, T., Pompilio, G., & Polvani, G. (2000). Minimally invasive direct coronary artery bypass grafting: midterm results and quality of life. The Annals of thoracic surgery, 70(2), 456-460.
9. Kapetanakis, E. I., Stamou, S. C., Petro, K. R., Hill, P. C., Boyce, S. W., Bafi, A. S., & Corso, P. J. (2008). Comparison of the Quality of Life After Conventional Versus Off‐Pump Coronary Artery Bypass Surgery. Journal of cardiac surgery, 23(2), 120-125.
10. Bonaros, N., Schachner, T., Wiedemann, D., Oehlinger, A., Ruetzler, E., Feuchtner, G., ... & Bonatti, J. (2009). Quality of life improvement after robotically assisted coronary artery bypass grafting. Cardiology, 114(1), 59-66.
11. Teman, N. R., Hawkins, R. B., Charles, E. J., Mehaffey, J. H., Speir, A. M., Quader, M. A., ... & Investigators for the Virginia Cardiac Services Quality Initiative. (2021). Minimally invasive vs open coronary surgery: a multi-institutional analysis of cost and outcomes. The Annals of Thoracic Surgery, 111(5), 1478-1484.
12. Rumsfeld, J. S., Magid, D. J., Plomondon, M. E., Sacks, J., Henderson, W., Hlatky, M., ... & Veterans Affairs Angina With Extremely Serious Operative Mortality (AWESOME) Investigators. (2003). Health-related quality of life after percutaneous coronary intervention versus coronary bypass surgery in high-risk patients with medically refractory ischemia. Journal of the American College of Cardiology, 41(10), 1732-1738.
13. Creber, R. M., Dimagli, A., Spadaccio, C., Myers, A., Moscarelli, M., Demetres, M., ... & Gaudino, M. (2022). Effect of coronary artery bypass grafting on quality of life: a meta-analysis of randomized trials. European Heart Journal-Quality of Care and Clinical Outcomes, 8(3), 259-268.
14. Subih, M., Elshatarat, R. A., Sawalha, M. A., Almarwani, A. M., Alhadidi, M., Alrahahleh, M., ... & Mohamed, N. A. (2024). Exploring the Impact of Cardiac Rehabilitation Programs on Health-Related Quality of Life and physiological outcomes in patients Post Coronary artery bypass grafts: a systematic review. Reviews in Cardiovascular Medicine, 25(4), 145.
15. Mohammad Razi, A. A., Amir, M. A., & Dimon, M. Z. (2021). Quality of life following Minimally Invasive Direct Coronary Artery Bypass Grafting (MIDCABG) versus conventional open-heart coronary artery bypass grafting (CABG): a 3-year data from a single centre. Journal of Clinical and Health Sciences (JCHS), 6(2), 36-42.
16. Uymaz, B., Sezer, G., Coşkun, P. K., Tarcan, O., Özleme, S., & Aybek, T. (2014). Clinical outcome, pain perception and activities of daily life after minimally invasive coronary artery bypass grafting. Anatolian Journal of Cardiology/Anadolu Kardiyoloji Dergisi, 14(2).
17. Puskas, J. D., Williams, W. H., Mahoney, E. M., Huber, P. R., Block, P. C., Duke, P. G., ... & Guyton, R. A. (2004). Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost, and quality-of-life outcomes: a randomized trial. Jama, 291(15), 1841-1849.