Doi 10.17992/lbl.2026.10. 912

Kristjana Lind Olafsdottir¹

Luis Gisli Rabelo²

Boðvar Pall Asgeirsson¹

Matthildur Maria Magnusdottir¹

Sigurður Ragnarsson³

Tomas Gudbjartsson^1,4

 

 

¹Faculty of Medicine, University of Iceland, ²Department of Cardiothoracic Surgery, Landspítali University Hospital, ³Department of Cardiothoracic Surgery, Skåne University Hospital, ⁴Department of Cardiothoracic Surgery, Landspítali University Hospital

Correspondance Kristjana Olafsdottir klo12@hi.is

Introduction: Most studies comparing off-pump and on-pump coronary artery bypass grafting (CABG) have primarily focused on short-term outcomes. The aim of this study was therefore to evaluate and compare long-term complications and survival between these surgical approaches.

Material and methods: This retrospective study included 2337 patients who underwent primary isolated CABG in Iceland between 2001-2021; 397 (17,0%) performed Off-Pump and 1940 (83,0%) On-Pump. The complications stroke, myocardial infarction (MI), percutaneous coronary intervention (PCI), repeat CABG and death; combined as major adverse cardiovascular and cerebrovascular events (MACCE), were compared between the groups after 1:1 propensity score matching (377 pairs). Long-term survival and MACCE-free survival were estimated using the Kaplan-Meier method and multivariable Cox regression.

Results: Before matching, patients in the On-Pump group had more extensive coronary artery disease and were more often operated on acutely. At 10-year follow-up, the cumulative incidence of PCI (14.0% in the Off-Pump group vs. 10.2% in the On-Pump group, p=0.110), MI (9.0% vs. 8.0%, p=0.784), stroke (4.6% vs. 6.8%, p=0.090) and repeat CABG (0.9% vs. 0.0%, p=0.090) were comparable between groups in the matched cohort. MACCE-free survival (71.0% in the Off-Pump group vs. 71.4% in the On-Pump group, p=0.74) and overall survival (78.5% vs. 73.2%, p=0.095) at 10 years was also comparable between groups. Furthermore, multivariate analysis showed similar overall survival for both surgical techniques (HR: 0.81; 95%-CI: 0.60-1.09; p=0,156).

Conclusions: The long-term outcomes following CABG in Iceland are favorable for both on-pump and off-pump procedures, both in terms of survival and long-term complications.

Figure 1. A flowchart of the study population.

Figure 2. 10-year MACCE-free survival among patients who underwent CABG in Iceland between 2001 and 2021 in the matched cohort, for both Off-Pump and On-Pump procedures.

 

Figure 3. 10-year overall survival among patients who underwent CABG in Iceland between 2001 and 2021 in the matched cohort, for both Off-Pump and On-Pump procedures. 

 

Table I. Comparison of patients who underwent On-Pump and Off-Pump coronary artery bypass grafting, before and after matching. Variables are presented as counts (%) or median [interquartile range].

 

	Unmatched			Matched
	On-Pump n = 1940	Off-pump n = 397	SMD	On-Pump n = 377	Off-pump n = 377	SMD
Baseline characteristics
Age, years	67.0 [61.0, 73.0]	67.0 [60.0, 73.0]	0.093	67.0 [61.0, 73.0]	66.0 [60.0, 73.0]	0.087
Sex (male)	1618 (83.4)	315 (79.3)	0.104	303 (80.4)	306 (81.2)	0.02
BMI (kg/m2)	28.0 [25.5, 30.8]	28.1 [25.3, 31.0]	0.015	27.8 [25.2, 30.5]	28.1 [25.4, 31.0]	0.095
COPD	145 (7.5)	31 (7.8)	0.013	29 (7.7)	30 (8.0)	0.01
History of renal failure	112 (5.8)	17 (4.3)	0.068	16 (4.2)	16 (4.2)	<0.001
Presenting with myocardial infarction	587 (30.3)	104 (26.2)	0.09	88 (23.3)	98 (26.0)	0.062
LVEF £ 30%	156 (8.0)	23 (5.8)	0.089	23 (6.1)	22 (5.8)	0.011
NYHA-classification III/IV	1112 (57.3)	266 (67.0)	0.201	246 (65.3)	254 (67.4)	0.045
EuroSCORE II	1.5 [1.0, 2.6]	1.4 [0.9, 2.3]	0.074	1.4 [0.9, 2.2]	1.4 [0.9, 2.3]	0.079
Three-vessel disease	1582 (81.5)	306 (77.1)	0.11	286 (75.9)	289 (76.7)	0.019
Left main stenosis	792 (40.8)	185 (46.6)	0.117	182 (48.3)	170 (45.1)	0.064
Coronary artery disease risk factors
HTN	1291 (66.5)	248 (62.5)	0.085	244 (64.7)	231 (61.3)	0.071
DM	371 (19.1)	65 (16.4)	0.072	60 (15.9)	61 (16.2)	0.007
Dyslipidemia	1042 (53.7)	225 (56.7)	0.06	209 (55.4)	210 (55.7)	0.005
History of smoking	434 (22,4)	86 (21,7)	0,017	92 (24,4)	80 (21,2)	0,076
Family history	954 (49.2)	209 (52.6)	0.069	193 (51.2)	201 (53.3)	0.042
Surgical characteristics
Nonelective surgery	1112 (57.3)	167 (42.1)	0.309	178 (47.2)	166 (44.0)	0.064
Operative time	204.0 [180.0, 232.2]	220.0 [185.0, 260.0]	0.298	210.5 [190.0, 240.0]	219.0 [185.0, 255.0]	0.092
LIMA used	1834 (94.5)	375 (94.5)	0.003	357 (94.7)	356 (94.4)	0.012
Distal anastomosis	3.0 [3.0, 4.0]	3.0 [3.0, 4.0]	0.056	4.0 [3.0, 4.0]	3.0 [3.0, 4.0]	0.103
Year of surgery	2010.0 [2005.0, 2014.0]	2006.0 [2004.0, 2009.0]	0.735	2006.0 [2003.0, 2009.0]	2006.0 [2004.0, 2009.0]	0.012

SMD, Standardized mean difference; BMI, body mass index; COPD, chronic obstructive pulmonary disease; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association; EuroSCORE II, European System for Cardiac Operative Risk Evaluation II; HTN, hypertension; DM, diabetes mellitus; LIMA, left internal mammary artery.

Table II. Cumulative incidence of long-term major adverse cardiovascular and cerebrovascular events (MACCE) at 10 years, before and after matching.

 

	Unmatched			Matched
	On-Pump n = 1940	Off-Pump n = 397	p	On-Pump n = 377	Off-Pump n = 377	p
MACCE (%)
PCI	9.7	13.6	0.020	10.2	14.0	0.110
Death	10.3	9.5	0.780	9.7	13.6	0.312
MI	8.1	8.5	0.944	8.0	9.0	0.784
Stroke	6.9	4.7	0.170	6.8	4.6	0.290
Re-CABG	0.2	0.9	0.101	0.0	0.9	0.090

Table III. Main predictors of mortality.

Predictors	Hazard ratio	95% CI	p
Age	1.10	1.07-1.12	<0.001
Male	1.00	0.70-1.44	0.986
BMI	0.99	0.96-1.03	0.576
COPD	1.92	1.25-2.93	0.003
Renal failure	2.98	1.87-4.76	<0.001
DM	1.38	0.94-2.02	0.097
LVEF £ 30%	2.26	1.39-3.67	0.001
EuroSCORE II	1.05	1.01-1.10	0.010
Three-vessel disease	1.01	0.69-1.47	0.973
Nonelective surgery	0.77	0.56-1.06	0.112
Off-Pump surgery	0.81	0.60-1.09	0.156