04. tbl. 98. árg. 2012
Outcome of mitral valve replacement in Iceland
Introduction: Mitral valve replacement (MVR) is the second most common valvular replacement procedure after aortic valve replacement (AVR). Studies on the outcome of MVR in Iceland have been missing. We therefore studied short and long-term results following MVR in Iceland.
Material and methods: A retrospective nationwide study on 64 patients (mean age 59 years, 63% males) that underwent 66 MVR procedures in Iceland between 1990-2010. Clinical data was retrieved from patient charts and overall survival estimated. The mean follow-up was 7.4 years.
Results: Mitral regurgitation or stenosis was the indication for MVR in 71% and 27% of cases, respectively. Nine patients had endocarditis and 8 a recent myocardial infarction. The mean logEuroSCORE was 14.9% (range 1.5-88.4), 83% of the patients were in NYHA class III/IV preoperatively and 24% had previously undergone cardiac surgery. A biological valve was implanted in six cases and a mechanical valve used in 60 cases. Concomitant CABG was performed in 41% of patients and AVR in 20%. Perioperative myocardial infarction (26%), acute respiratory failure (17%), reoperation for bleeding (15%) and acute renal failure requiring dialysis (9%) were the most common major complications. Three patients required extracorporeal membrane oxygenation (ECMO) and six patients an intra-aortic balloon pump (IABP) postoperatively. Minor complications were noted in 61% of cases. Six patients died within 30 days (9%) and five year survival was 69%.
Conclusion: The frequency of complication following MVR was high and represents the severity of the underlying heart disease. The operative mortality in the current study was in the lower range compared to other studies.
Ragnarsson S1, Sigurdsson MI1, Danielsen R2,3, Arnorsson T1, Gudbjartsson T1,3
Departments of 1Cardiothoracic surgery and 2Cardiology, Landspitali University Hospital, 3Faculty of Medicine, University of Iceland.
Table I: Demographics for the 64 patients that underwent 66 mitral valve replacement procedures in Iceland from 1990 to 2009. Number of patients and % in parentheses, except means with standard deviation for age and EuroSCORE.
| Male | 40 (63) |
| Age (years) | 59 ± 14 |
| Hypertension | 13 (20) |
| Diabetes mellitus | 2 (3) |
| History of smoking | 41 (62) |
| Body mass index (BMI) ≥25 kg/m2 | 32 (49) |
| Chronic obstructive pulmonary disease (COPD) | 7 (11) |
| Renal failure (preoperative creatinine > 200 µmol/L) | 7 (11) |
| Active endocarditis | 10 (15) |
| Coronary artery disease | 40 (56) |
| Pulmonary hypertension, systolic pressure > 60 mmHg | 18 (27) |
| Previous open heart surgery | 16 (24) |
| NYHA class | |
| I+II | 9 (14) |
| III + IV | 57 (87) |
| ASA*score | |
| I+II | 0 |
| III | 41 (62) |
| IV | 25 (38) |
| EuroSCORE (log) | 14.9 ± 20.0 |
* American Association of Anesthesiology
Table II: Causes of mitral regurgitation in patients that underwent mitral valve replacement in Iceland in 1990-2009.
| Number (%) | |
| Mitral valve prolapse | 17 (36) |
| Chordae tendinae rupture | 4 (9) |
| Endocarditis | 9 (19) |
| Chronic ischemic mitral regurgitation | 4 (9) |
| Papillary muscle rupture in acute myocardial infarction | 2 (4) |
| Reoperation for re-regurgitation after previous mitral repair | 5 (11) |
| Reoperation after previous mitral valve replacement (paravalvular leakage, prosthesis thrombosis, endocarditis) | 4 (9) |
| Mitral valve calcification | 2 (4) |
| Total | 47 |
Table III: Results of preoperative echocardiography on patients that underwent mitral valve replacement in Iceland in 1990-2009. Given are means with standard deviation, except otherwise stated.
|
Mitral insufficiency (n=47) |
Mitral stenosis (n=18) |
|
| Left ventricular ejection fraction (%) | 53 ± 16 | 57 ± 12 |
| Left atrium diameter (mm) | 51 ± 11 | 52 ± 10 |
| Left ventricular end-diastolic diameter (mm) | 61 ± 10 | 51 ± 7 |
| Left ventricular end-systolic diameter (mm) | 42 ± 10 | 35 ± 8 |
| Mean pressure gradient across the mitral valve (mmHg) | 11 ± 5 | |
| Valve orifice area (cm2) | 1.2 ± 0.4 | |
| Mitral valve insuffictiency (0-3) | 2.8 ± 0.5 | 1.4 ± 0.8 |
| Proportion with mitral valve insufficiency > 2/3 (%) | 88 | 9 |
Table IV: Types of valve prostheses implanted in 64 patients that underwent 66 mitral valve replacements in Iceland in 1990-2009.
| Number (%) | |
| Mechanical prostheses | 60 (91) |
| St Jude Medical® bileaflet | 27 (41) |
| Carbomedics® bileaflet | 33 (50) |
| Biological prostheses | 6 (9) |
| Carpentier Edwards® Perimount MagnaTM | 2 (3) |
| Carpentier Edwards® PorcineTM | 1 (2) |
| St. Jude Medical® EpicTM | 3 (5) |
Table V: Short term complications in patients that underwent mitral valve replacement in Iceland between1990 and 2009. The number of patients is shown with percentage in parentheses. Patients can have more than one complication.
| Number (%) | |
| Serious complications | 31 (47) |
| Perioperative myocardial infarction* | 15 (26) |
| Severe respiratory failure | 11 (17) † |
| Reoperation for bleeding | 10 (15) |
| Perioperative heart failure requiring intraaortic ballon pump (n=6) or ECMO (n=3) treatment | 9 (14) |
| Acute renal failure requiring dialysis | 6 (9) |
| Permanent stroke | 2 (3) |
| Reoperation for paravalvular leakage | 1 (2) |
| Deep sternal wound infection/sternum dehiscense | 2 (3) |
| Endocarditis | 1 (2) |
| Minor complications | 40 (61) |
| New onset atrial fibrillation ‡ | 17 (45) |
| Minor cardiac injury § | 18 (31) |
| Pleural fluid requiring drainage | 17 (26) |
| Pneumonia | 8 (12) |
| Acute renal injury ¶ that did not require dialysis | 5 (8) |
| Pericardial fluid requiring drainage | 5 (8) |
| Urinary tract infection | 3 (6) |
| Bradycardia requiring pacemaker insertion | 2 (3) |
| Superficial wound infection | 2 (3) |
* New ST-elevations on EKG or postoperative serum CK-MB > 100 µg/L in patients that did not have ongoing or recent myocardial infarction.
† Mechanical ventilation for more than one week. Six of these patients got tracheostomy
‡ only including 38 patients that did not have atrial fibrillation preoperatively
§ postoperative serum CK-MB between 70-100 µg/L in patients that did not have a recent preoperative myocardial infarction.
¶ S-creatinine > 200 µmol/L in patients with not elevated values preoperatively.
Tafla VI: Overview of patients that died within 30 days after mitral valve replacement in Iceland 1990-2009.
| No. | Age/sex | NYHA class/ EuroSCORE (log) | Diagnosis | Biological valve | Concomitant procedure | Attempted repair | Cross clamp time | Post operative IABP/ ECMO | Transfusion (units of red blood cells) | Reoperation for bleeding | Survival (days) | Cause of death |
| 1 | 74/M | IV /74.5 | Reop for mitral insufficiency after same day mitral valve repair | + | − | − | 162 | −/− | 5 | − | 3 | Perioperative myocardial infarction |
| 2 | 47/F | IV 88.4 | Insufficiency due to endocarditis | − | − | − | 120 | −/− | 37 | + | 19 | Sepsis |
| 3 | 71/M | IV /31.1 | Acute myocardial infarction with papillary muscle rupture | − | CABG | − | 311 | −/+ | 23 | − | 4 | Acute myocardial infarction, ARDS |
| 4 | 60/M | III /20.2 | Insufficiency due to endocarditis | − | − | + | 285 | +/+ | 87 | − | 9 | Multiple organ failure |
| 5 | 65/M | III /11.0 | Ischemic mitral regurgitation | − | CABG | + | 355 | +/− | 15 | − | 1 | Perioperative myocardial infarction |
| 6 | 50/M | III / 5.5 | Insufficiency due to posterior mitral valve prolapse | + | AVR | − | 222 | −/+ | 38 | + | 5 | Multiple organ failure, perioperative myocardial infarction |