| 1. |
- Nozohoor, Shahab
(författare)
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Aortic Valve Replacement: The Influence of Prosthesis-Patient Mismatch for Left Ventricular Remodeling, Cardiac Function and Survival
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The best valve substitute for aortic valve replacement (AVR) in terms of hemodynamic performance, durability, incidence of complications, and survival remains the subject of much debate. It has been suggested that valve performance is influenced by the potentially modifiable variable prosthesis-patient mismatch (PPM). PPM has been reported to be detrimental for survival and symptom resolution mainly due to the promotion of unfavorable prosthesis hemodynamics with secondary impaired left ventricular remodeling. Nevertheless, an increasing number of studies with various study designs and outcomes present conflicting results. Thus, there is no convincing evidence for PPM’s detrimental effects. The aims of this research were to evaluate the impact of PPM on in-hospital complications and survival, to evaluate whether postoperative heart failure can be detected using brain-type natriuretic peptide (BNP) as a predictive biomarker, to investigate the influence of PPM in bioprostheses with respect to recovery of left ventricular diastolic function and left ventricular mass regression, and to evaluate the influence of prosthesis-patient mismatch on left ventricular remodeling following aortic valve replacement for severe valve insufficiency. The present work demonstrated that PPM was not associated with low cardiac output syndrome, but rather an independent risk factor for a neurological event during the postoperative period after valve replacement. PPM had no impact on either early or late mortality. Postoperative heart failure following AVR was associated with a high early postoperative mortality and was predicted by elevated BNP levels on arrival in the ICU. PPM did not impair left ventricular mass regression or the recovery of diastolic function. Left ventricular remodeling was initiated regardless of preoperative left ventricular ejection fraction or PPM. In conclusion, the clinical relevance and the prevention of PPM seem subordinate and to improve patient outcome, priority should be given to the design of a durable, non-thrombogenic prosthesis permitting easy handling and reducing surgical complexity.
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| 2. |
- Nozohoor, Shahab, et al.
(författare)
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B-Type Natriuretic Peptide as a Predictor of Postoperative Heart Failure After Aortic Valve Replacement.
- 2009
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Ingår i: Journal of Cardiothoracic and Vascular Anesthesia. - : Elsevier BV. - 1532-8422 .- 1053-0770. ; 23, s. 161-165
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: B-type natriuretic peptide (BNP) has been established as a biomarker for heart failure. The objective was to evaluate BNP measured on arrival in the intensive care unit (ICU) as a predictor for heart failure defined as need for inotropic support or IABP beyond 24 hours postoperatively after aortic valve replacement. DESIGN: A prospective, observational study. SETTING: A cardiothoracic surgery unit at a tertiary level hospital. PARTICIPANTS: One hundred sixty-one patients undergoing aortic valve replacement. MEASUREMENTS AND MAIN RESULTS: Two levels of BNP were evaluated: the median (BNP >133 pg/mL) and a cutoff (BNP >82 pg/mL) based on receiver-operating characteristic (ROC) analysis. Uni- and multivariate analysis were performed to identify predictors of postoperative heart failure. Patients with postoperative heart failure (n = 37) showed a more than 10-fold increase in 30-day mortality (8.1%, 3/37) compared with patients without postoperative heart failure (0.8%, 1/124) (p = 0.038). Elevated postoperative BNP levels were identified as an independent predictor of postoperative heart failure: BNP >82 pg/mL (p = 0.004) and BNP >133 pg/mL (p = 0.013). The area under the ROC curve for BNP as a predictor of postoperative heart failure was 0.69. CONCLUSION: Postoperative heart failure after aortic valve replacement is still a very serious condition with increased early mortality. The results of the present study suggest that an elevated BNP level on arrival in the ICU is an independent predictor of postoperative heart failure after aortic valve replacement. In the authors' opinion, an increased BNP level on arrival in the ICU may support early diagnosis and allow optimal management of heart failure after aortic valve replacement.
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| 3. |
- Nozohoor, Shahab, et al.
(författare)
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Influence of prosthesis-patient mismatch on diastolic heart failure after aortic valve replacement.
- 2008
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Ingår i: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 85:4, s. 1310-1318
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Bioprostheses for supraannular placement have been developed to optimize the hemodynamic performance after aortic valve replacement. To evaluate the potential benefit of this design, we analyzed the influence of prosthesis-patient mismatch on diastolic function and left ventricular mass regression and evaluated the clinical performance of the Sorin Soprano and Medtronic Mosaic in the aortic position. METHODS: A total of 372 patients underwent aortic valve replacement between July 2004 and February 2007, receiving either a Sorin Soprano (n = 235) or a Medtronic Mosaic (n = 137) prosthetic valve. Echocardiographic and clinical data were collected prospectively, and follow-up was performed in April 2007. Multivariate analyses were used to identify differences in hemodynamic performance, diastolic function, left ventricular mass regression, and predictors of impaired survival. Kaplan-Meier survival curves and log-rank tests were used to compare postoperative outcomes. RESULTS: The 30-day mortality was 1.7% (4 of 235 patients) in the Sorin Soprano group and 2.9% (4 of 137 patients) in the Medtronic Mosaic group (p = 0.473). Neither prosthesis-patient mismatch nor type of prosthesis was a significant predictor of early or late mortality. Diastolic heart failure was a predictor of poor survival (p = 0.004); however, the recovery of diastolic function was not significantly influenced by prosthesis-patient mismatch. Neither moderate (indexed effective orifice area < 0.85 cm(2)/m(2)) nor severe (indexed effective orifice area < 0.65 cm(2)/m(2)) prosthesis-patient mismatch resulted in a significantly impaired left ventricular mass regression. CONCLUSIONS: Prosthesis-patient mismatch was not an independent predictor of poor survival, impaired left ventricular mass regression, or recovery of diastolic function. The Sorin Soprano and the Medtronic Mosaic bioprostheses demonstrated comparable hemodynamic performance and excellent clinical outcome without signs of structural valve deterioration during follow-up.
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| 4. |
- Nozohoor, Shahab, et al.
(författare)
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The influence of patient-prosthesis mismatch on in-hospital complications and early mortality after aortic valve replacement
- 2007
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Ingår i: Journal of Heart Valve Disease. - 0966-8519. ; 16:5, s. 475-482
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim of the study: The study aim was to analyze the relationship between patient-prosthesis mismatch (PPM) and in-hospital complications and mortality after aortic valve replacement (AVR). Methods: AVR was performed in 1,819 patients between January 1996 and July 2006. Follow up investigations were performed after a mean of 4.3 years (range: 0 days to 10.6 years). Univariate and multivariate analysis were used to evaluate risk factors for in-hospital complications and mortality in patients with prosthesis mismatch. Actuarial statistics were used to calculate survival rates. Results: Multivariate analysis showed that PPM (defined as indexed effective orifice area 0.85 cm(2)/m(2)) was associated with an increased risk of postoperative neurological events (OR 2.26, 95% Cl 1.05-4.83, p = 0.037). There were no significant differences in 30-day mortality between the PPM and nonPPM groups. Neither was any significant difference found between the two groups regarding long-term survival adjusted for significant risk factors for death after AVR. Conclusion: The results suggest PPM to be an independent predictor of postoperative neurological complications in patients undergoing AVR. However, PPM did not negatively influence either short- or long-term survival. PPM may play an important role in selected categories of patients, and should be considered in order to avoid postoperative neurological complications.
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