Objective: To investigate long-term complications and survival following aortic valve replacement (AVR) in patients with aortic stenosis (AS) in Iceland.

Material and methods: Included were 156 patients (average age 71.7 yrs, 64.7% males) that underwent AVR for AS at Landspitali between 2002 and 2006. A mechanical prosthesis was used in 29 patients (18.6%) and a bioprosthesis in 127. Long-term complications and operation-related admissions were registered from hospital and outpatient records until April 1, 2010. Overall survival was estimated and compared with the Icelandic population of the same age and gender.

Results: The mean preop. EuroSCORE(st) was 6.9%, the max. transvalvular pressure gradient 74.1 mmHg and the left ventricular ejection fraction (LVEF) (57.2%). At six months following AVR the maximal pressure gradient was 19.8 mmHg (range; 2.5-38). Echocardiography results were not available for 23.6% of the patients 6 months postoperatively. In the follow-up period one in four patients was admitted due to valve-related problems. Re-admission rate was 6.0/100 patient-years (pt-y); most commonly due to cardiac failure (1.7/100 pt-y), emboli (1.6/100 pt-y), hemorrhage (1.6/100 pt-y), endocarditis (0.7/100 pt-y) and myocardial infarction (0.4/100 pt-y). Survival at 1 and 5 year was 89.7% and 78.2%, respectively, making survival comparable to the estimated survival of Icelanders of the same age and gender.

Conclusions: The rate of long-term complications following AVR in Iceland is in line with other studies. The same applies to long-term survival, which was similar to that of the Icelandic population of the same age and gender.

 

 

Table I. Echocardiography results preoperatively and approximately six months post-operatively for patients that underwent aortic valve replacement for aortic stenosis in Iceland between 2002 and 2006. Echocardiography results were found for 63 patients; including information on left ventricular ejection fraction for 52 patients and left ventricular end diastolic diameter, septum thickness and maximum aortic valve pressure gradient for 49 patients. Given are means with standard deviation for continuous variables and number of patients and percentages for categorial variables.

 

Results	Preop.	1 week postop.	6 months postop.
Ejection fraction (%)	57.2 ± 7.7	50.4 ± 9.1	54.8 ± 8.6
LVEDD (cm)	5.3 ± 0.9	5.2 ± 0.8	5.2 ± 0.8
Maximum aortic valve pressure gradient (mmHg)	74.1 ± 25.3	28.1 ± 10.1	19.8 ± 7.3
Septum thickness (cm)	1.4 ± 0.3	1.5 ± 0.3	1.3 ± 0.3
Valvular leak (n, %)	-	7 (4.5)**	9 (5.8) **
Paravalvular leak (n, %)	-	0	3 (1.9)

* LVDD = left ventricular diastolic diameter, ** in all cases mild regurgitation

 

 

Table II. Comparison of several major studies and the present study regarding long-term complications following aortic valve replacement. Number of complications are given per 100 patient-years.

 

Study (year)	Type of prosthesis	Patient years	Hemorrhage	Emboli	Endocarditis	Valvular thrombosis
Emery et al. (2005)7	St. Jude MedicalÒ mechanical	21,741	2.7	1.9	0.2	0.06
Khan et al. (2001)5	St. Jude MedicalÒ mechanical	3,881	2.0	2.5	0.3	0.3
Butchart et al. (2001)22	Medtronic HallÒ mechanical	5,120	1.2	2.3	0.4	0.04
Khan et al. (2001)5	Bioprostheses	3,387	0.7	2.1	0.6	0
Bach et al. (2005)23	Medtronic FreestyleÒ	4,488	0.8	2.7	0.4	0.05
Eichinger et al. (2008)11	St. Jude Medical BiocorÒ	3,321	0.8	2.1	0.5	Not reported
Viktorsson (2011)	Dfferent types	749	1.6	1.6	0.7	0.0

 

 

Figure 1. The rate of long-term complications for 156 patients that underwent aortic valve replacement for aortic stenosis in Iceland between 2002 and 2006. The rate of re-admissions for each complication is given per 100 patient years. Four patients had more than one complication.

 

 

Figure 2. Overall survival of patients that underwent aortic valve replacement for aortic stenosis in Iceland between 2002 and 2006, together with 95% confidence interval (broken lines). The gray line shows the estimated survival of a reference group of Icelanders of the same sex and age as the patient population.

 

 

Figure 3. Disease-specific survival of patients that underwent aortic valve replacement for aortic stenosis in Iceland between 2002 and 2006. Broken lines indicate 95% confidence interval.