Objective: To study the outcome of open heart surgery in an increasing population of elderly patients in Iceland.

Material and methods: A retrospective study of patients (n=876) that underwent coronary artery bypass (CABG) or aortic valve replacement (AVR) for aortic stenosis in Iceland 2002-2006. Complication rates, operative mortality and long-term survival were compared between patients older (n=221, 25%) and younger (n=655, 75%) than 75 years. Long-term survival of the older group was compared to an age and sex matched reference population.

Results: Older patients had a higher incidence of atrial fibrillation (57% vs. 37%, p<0.001), stroke (5% vs. 1%, p=0.009) and operative mortality (9% vs. 2%, p<0.001) following CABG. Length of ICU stay was similar but total length of stay was one day longer in the older cohort. Following AVR, older patients had a higher incidence of atrial fibrillation (90% vs. 71%, p=0.006), ARDS (19% vs. 7%, p=0.04), myocardial infarction (21% vs. 8%, p=0.05) and operative mortality (11% vs. 2%, p=0.04). The ICU stay was a day longer and the total length of stay was about four days longer in the older cohort. A total of  75% of the older patients were alive five years after CABG, compared to 74% of the reference population (p=0.87). Similar numbers for AVR were 65% for the patients compared to 74% in the reference population (p=0.06).

Conclusion: The rate of complications, operative mortality and length of hospital stay is higher in patients older than 75 years compared to younger patients. Survival of the older group of patients indicates good long-term results after open heart surgery for this patient cohort.

 

Table I. Comparison of patient demographics, cardiovascular risk factors and results of preoperative diagnostic tests for older (≥75 years) and younger patients that underwent CABG/OPCAB only or AVR ± CABG in Iceland 2002-2006. Given are number of patients and percentage in parenthesis except for number of affected coronary vessels, ejection fraction, EuroSCORE were means are displayed.

 

	All			CABG/OPCAB only			AVR ± CABG
	Younger patients (n=655)	Older patients (n=221)	p-value	Younger patients (n=571)	Older patients (n=149)	p-value	Younger patients (n=84)	Older patients (n=72)	p-value
Male (%)	543 (83)	108 (67)	0.001	483 (85)	108 (73)	0.001	60 (71)	41(57)	0.09
Diabetes (%)	110 (17)	25 (11)	0.07	95 (17)	14 (9)	0.04	69 (18)	61 (15)	0.83
Hypertension (%)	405 (62)	146 (66)	0.29	346 (61)	97 (65)	0.36	59 (70)	49 (66)	0.9
Dyslipidemia (%)	385 (59)	104 (47)	0.001	346 (61)	75 (50)	0.03	39 (47)	29 (41)	0.55
Smoking (%)	179 (27)	23 (11)	<0.001	161 (28)	13 (9)	<0.001	18 (21)	10 (14)	0.31
Chronic heart failure (%)	88 (13)	56 (25)	<0.001	71 (12)	25 (17)	0.21	17 (20)	31 (43)	0.001
Number of affected coronary vessels	2.6	2.4	0.001	2.6	2.9	0.02	1.2	1.3	0.45
Left ventricular ejection fraction (LVEF)	53	52	0.42	53	53	0.51	58	56	0.06
Maximum aortic valve gradient (mmHg)	n/a	n/a	n/a	n/a	n/a	n/a	70	78	0.05
EuroSCORE (st)	4.4	7.8	<0.001	4.3	7.4	<0.001	5.4	8.7	<0.001

 

 

Table II. Comparison of operative related factors in older (≥75 years) and younger patients that underwent CABG/OPCAB only or AVR ± CABG in Iceland between 2002 and 2006. Variables are presented with means and range except for type of operation that is given with number of patients and % in parenthesis.

 

	CABG/OPCAB only			AVR ± CABG
	Younger patients (n=571)	Older patients (n=149)	p-value	Younger patients (n=84)	Older patients (n=72)	p-value
Off pump coronary artery bypass (OPCAB) (%)	164 (29)	43 (29)	–	–	–	–
Use of extracorporeal bypass (ECC)	407 (71)	106 (71)	0.95	100%	100%	–
AVR only (%)	–	–		42 (50)	28 (39)
AVR + CABG (%)	–	–	–	42 (50)	48 (61)	0.55
Operation-time, min (range)	204 (85-555)	206 (110-370)	0.81	277 (140-560)	288 (135-690)	0.44
Aortic X-clamp time, min (range)	42 (13-191)	42 (19-134)	0.90	121 (57-280)	127 (64-264)	0.37
Chest tube output <24 hrs postop, mL (range)	1021 (100-31820)	1097 (100-4425)	0.41	1229 (185-4980)	1106 (0-4760)	0.43
Transfusion of packed red cells, units (range)	2 (0-88)	3 (0-31)	0.02	6 (0-29)	9 (0-46)	0.03

Table III. Comparison of minor and major complications together with operative mortality in groups of  older (≥75 years) and younger patients that underwent CABG/OPCAB only or AVR± CABG in Iceland between 2002 and 2006.  Given are number of patients and percentage in parenthesis.

	All			CABG/OPCAB only			AVR ±CABG
	Younger patients (n=655)	Older patients (n=221)	p-value	Younger patients (n=571)	Older patients (n=149)	p-value	Younger patients (n=84)	Older patients (n=72)	p-value
Atrial fibrillation / flutter (%)	269 (41)	150 (68)	<0.001	209 (37)	85 (57)	<0.001	60 (71)	65 (90)	0.01
Drainage of pleural fluid(%)	80 (12)	35 (16)	0.21	70 (12)	24 (16)	0.27	10 (12)	11 (15)	0.7
Superficial wound infection (%)	58 (9)	13 (9)	0.96	52 (9)	13 (9)	0.99	6 (8)	7 (10)	0.77
Pneumonia (%)	36 (6)	31 (14)	<0.001	31 (5)	14 (9)	0.11	5 (6)	17 (24)	0.03
Urinary tract infection (%)	23 (4)	33 (15)	<0.001	12 (2)	15 (10)	<0.001	11 (13)	18 (25)	0.09
Any minor complication (%)	347 (53)	173 (78)	<0.001	284 (50)	107 (72)	<0.001	63 (75)	66 (92)	0.01
Myocardial infarction (%)	79 (12)	38 (17)	0.07	72 (13)	23 (15)	0.44	7 (8)	15 (21)	0.05
Stroke (%)	11 (2)	11 (5)	0.01	8 (1)	8 (5)	0.01	3 (4)	3 (4)	0.82
Renal failure requiring dialysis (%)	9 (1)	3 (1)	0.99	9 (2)	3 (2)	0.99	0 (0)	0 (0)	1.00
Deep wound infection / mediastinitis / endocarditis (%)	5 (0.8)	1 (0.5)	0.99	5 (1)	1 (1)	0.79	0 (0)	0 (0)	1.00
Sternum insufficience (%)	14 (2)	10 (5)	0.10	12 (2)	7 (5)	0.14	2 (2)	3 (4)	0.86
Multiple organ failure / ARDS (%)	21 (3)	22 (10)	<0.001	15 (3)	8 (5)	0.15	6 (7)	14 (19)	0.04
Any major complication (%)	112 (17)	69 (32)	0.01	99 (17)	42 (28)	0.004	13 (16)	27 (38)	0.03
Operative mortality (%)	12 (2)	21 (10)	<0.001	10 (2)	13 (9)	<0.001	2 (2.4)	8 (11.1)	0.003

 

Figure 1. Age distribution of patients that underwent open heart surgery (coronary artery bypass and/or aortic valve replacement) in Iceland between 2002 and 2006.

Figure 2. Kaplan-Meier plot of overall survival of patients 75 years or older that underwent CABG/OPCAB (Fig. 2a) ± AVR (Fig. 2b) in Iceland between 2002 and 2006 (blue line), together with 95% confidence intervals (broken blue lines). For comparison the survival of a reference population of Icelanders of the same age and sex is shown with the black line. Survival at 12 and 36 months postoperatively is shown with numbers. The survival of neither the CABG/OPCAB or AVR-cohort differed significantly from the survival of the reference population.