Aref Amiri

Deutsches Herzzentrum Berlin, Berlín, Berlin, Germany

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Publications (19)27.72 Total impact

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    ABSTRACT: Background The role of intracardiac blood flow behavior within the context of manifestation and interventional success in patients with mitral regurgitation is unknown to date. The present study aims to assess left ventricular blood flow behavior characterized by kinetic energy (KE) in patients with mitral regurgitation before and after mitral valve surgery.Methods Patients with mitral regurgitation (mean age 56 ± 9 years) and the necessity for mitral valve repair (n = 6) or biological valve replacement (n = 4) received cardiac magnetic resonance before and after surgery and were compared with a group of healthy volunteers (n = 7; mean age 27 ± 7 years). Volumetric data and KE of the left ventricle were obtained for all subjects. KE normalized and nonnormalized to volume was calculated from four-dimensional flow magnetic resonance imaging. Mean KE and KE peaks (systolic, early-diastolic and late diastolic), and end-systolic phase duration were considered.ResultsEnd-diastolic, end-systolic and stroke volume were significantly higher in patients with mitral regurgitation than in healthy volunteers (P = 0.00, 0.01, and 0.00, respectively) and decreased significantly after surgery (P = 0.00, 0.01, and 0.00, respectively). A significant postoperative decrease of mean KE, systolic and early-diastolic KE peaks was observed (P = 0.01, 0.02, and 0.01, respectively). Late-diastolic KE peak remained high in postoperative patients (P = 0.58).Conclusion Intracardiac blood flow as characterized by measurements of KE is altered in patients with mitral regurgitation. Physiological flow conditions appear to not fully be restored with mitral valve surgery. J. Magn. Reson. Imaging 2015.
    Journal of Magnetic Resonance Imaging 04/2015; DOI:10.1002/jmri.24926 · 3.21 Impact Factor
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    A Amiri · E W Delmo Walter · R Hetzer
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    ABSTRACT: With increasing enthusiasm in minimally invasive surgery, several approaches and access are being performed with great precision. In this report, we illustrate and describe a minimal invasive approach to mitral valve surgery with optimal access under direct vision, the indications and patient selection, the surgical techniques, its advantages over the other approaches, and its simplicity and reproducibility.
    10/2014; 6(3):152-6.
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    ABSTRACT: We introduce a technique of posterior annulus shortening to augment leaflet coaptation which addresses the restrictive mitral leaflet mobility in ischemic mitral incompetence (IMI), and report its long-term outcome. Between 1992 and 2012, 75 patients (mean age, 64.6±10.4 years; median, 66.0 years; range, 35.0-86.1 years) underwent repair of IMI by posterior annulus shortening to augment leaflet coaptation surface area. This technique reduces the annular diameter to between 23 and 25 mm and decreases the valve orifice to between 3.5 to 4.5 cm(2), which is sufficient to ensure an adequate leaflet coaptation area. An untreated pericardial strip is used to reinforce the shortened annulus in order to avoid redilatation. This augments the posterior leaflet by increasing the ratio of leaflet area/valve orifice where the coaptation gap is the greatest. The tissue strip increases and heightens the area which the posterior leaflet offers to the anterior leaflet for coaptation during closure, making valve closure possible in advanced leaflet restriction. During a mean follow-up of 7.62±0.66 (median 8.53, range, 3.6-20.9) years, New York Heart Association (NYHA) functional class significantly improved, left ventricular ejection fraction (LVEF) increased and there was a tremendous abatement of MI (P<0.01). Annular area was reduced from 9.2 to 5.8 cm(2). Coaptation area was increased from a complete lack thereof to 6.6 mm(2) post-repair. CT showed posterior annulus size reduction from 70.4 to 54 mm and an increase in posterior leaflet length from 15.9 to 19.6 mm. A remarkable CT finding was the increase in coaptation length from 5.2 to 8.2 mm. Eighteen-year freedom from moderate MI, freedom from reoperation and survival rates were 80.7%±9%, 84.9%±4.2% and 65.1%±6.3%, respectively. Posterior annulus shortening with pericardial strip augmentation addressing the lack of leaflet coaptation is a simple, reproducible and highly effective technique to restore valve competence in IMI.
    The Thoracic and Cardiovascular Surgeon 02/2014; 62(S 01). DOI:10.1055/s-0034-1367401 · 0.98 Impact Factor
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    A Amiri · E Delmo Walter · R Hetzer
    Journal of Cardiothoracic Surgery 09/2013; 8(Suppl 1):O269-O269. DOI:10.1186/1749-8090-8-S1-O269 · 1.03 Impact Factor
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    ABSTRACT: Objectives: We investigated early, midterm, and long-term results following valve replacement with the "No-React" bioprosthesis in patients with active infective endocarditis (AIE).Patients and Methods Between February 2000 and February 2011, a total of 402 patients (median 61 years, 17 to 91 years) received "No-React" bioprostheses due to single valve AIE in 315 (aortic valve replacement n = 158, aortic conduit n = 30, mitral valve replacement n = 116, tricuspid valve replacement n = 11) and double valve AIE in 87 cases. Prosthetic AIE was found in 105 patients (26.1%). Mean follow-up was 2.8 ± 3.2 years (1 month to 11.4 years) with 1,124 patient years, completed in 97.1%. This retrospective study analyzes both prospectively updated data (n = 255) and patients recently operated upon (n = 147). Results: There was a highly significant difference in the survival between patients operated on urgently and patients operated on in an emergency (30-day, 1-, 5-, and 10-year survival were 80.9 ± 2.3%, 63.8 ± 2.9%, 48.3 ± 3.3%, and 39.7 ± 4.1% vs. 61.3 ± 4.5%, 45.0 ± 4.7%, 33.1 ± 4.6%, and 14.0 ± 5.1%, respectively, p < 0.001), due to native versus prosthetic AIE (p = 0.032), single versus double valve replacement (p = 0.005), and with or without abscess formation (p < 0.001). Thirty-day, 1-, 5-, and 10-year freedom from reoperation due to recurrent endocarditis were 100%, 95.1 ± 1.4%, 86.4 ± 2.6%, and 82.1 ± 3.6% and due to structural valve deterioration (SVD) were 100%, 100%, 98.9 ± 0.8%, and 91.4 ± 4.0%, respectively. There was no difference in prosthesis durability between the older (> 60 years) and the younger patients. Conclusions: Our experience in the use of "No-React" bioprostheses in patients with native and prosthetic AIE shows satisfactory early, midterm, and long-term results, in particular low rates of reoperation due to recurrent endocarditis and SVD. Because these prostheses are readily available and their implantation straightforward, we strongly recommend their use in patients with AIE. Patients' survival differed significantly depending on their surgical urgency. Early mortality was independently predicted by septic shock, abscess formation, and number of implanted valves besides age per 10 years.
    The Thoracic and Cardiovascular Surgeon 04/2013; 61(5). DOI:10.1055/s-0033-1337903 · 0.98 Impact Factor
  • The Thoracic and Cardiovascular Surgeon 01/2013; 61(S 01). DOI:10.1055/s-0032-1332313 · 0.98 Impact Factor
  • The Thoracic and Cardiovascular Surgeon 01/2013; 61(S 01). DOI:10.1055/s-0032-1332695 · 0.98 Impact Factor
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    ABSTRACT: We retrospectively compared early and long-term results of mitral (MV) and tricuspid valve (TV) repair in patients with isolated active infective atrioventricular valve (AV) endocarditis over a period of 23 years. Between April 1986 and December 2009, a total of 1,409 patients with active infective endocarditis (AIE) were operated upon. Of these, 106 (7.2%) patients (n = 69 men, age 2-84 years) underwent repair of AVE (MV n = 68, TV n = 38). Repair techniques included vegetectomy and leaflet resection, annular plication and annuloplasty, and pericardial patch leaflet and annular reconstruction without any artificial device. Perioperative characteristics, probability of survival, freedom from recurrence and reoperation, and predictors for early mortality were analyzed. Follow-up (0-23 years) was completed in 95% with a total of 667 patient years. The 30-day, 1-, 5- and 10-year survival rate for MV repair was 89.7 ± 0.4, 82.2 ± 4.6, 72.6 ± 5.5 and 56.5 ± 7.3% and for TV repair 94.7 ± 3.7, 88.7 ± 5.3, 69.4 ± 8.8 and 64.5 ± 9.5%, respectively (ns). Three patients (2.8%) had to undergo reoperation due to early failure of reconstruction (n = 2 MV, n = 1 TV). Freedom from valve-related reoperation at 1 and 10 years was 88.4 ± 4.1 and 75.4 ± 7.4% for the MV repair and 97.4 ± 2.6 and 93.94 ± 4.2% for the TV repair group (ns). Endocarditis reoccurred early in 2 MV repair patients (1.9%). Freedom from reoperation due to reinfection at 1 and 10 years after MV repair was 96.6 ± 2.3 and 91.6 ± 5.4% and after TV repair 100 and 83.3 ± 9.5%. Repair for AV endocarditis yields excellent results. It is associated with low operative mortality and provides satisfactory early and long-term survival and favorable freedom from recurrent endocarditis and repeat operation. It should be considered as the primary surgical option in these patients, and AV replacement should be performed only in cases of severe AV destruction that renders repair techniques impossible.
    Clinical Research in Cardiology 06/2011; 100(11):993-1002. DOI:10.1007/s00392-011-0331-2 · 4.56 Impact Factor
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    ABSTRACT: Perioperative echocardiographic imaging has become an indispensable component of contemporary mitral valve repair. Mitral valve reconstruction surgery was popularized by the French surgeon Alain Carpentier and has continuously gained popularity over prosthetic valve replacement. At our institution, the Deutsches Herzzentrum Berlin (DHZB), Roland Hetzer modified the Gerbode and the Paneth techniques of mitral valve reconstruction effectively without using fabric material.
    12/2010: pages 25-38;
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    ABSTRACT: The concept of using the echocardiography machine in the operating room fulfills the need for intraoperative diagnosis. Immediately after the completion of a surgical intervention the outcome can be verified and, if the initial results are not optimal, surgical correction may be performed. Examination by stethoscope in the operating room is not sufficient and it was discovered that patients were doing poorly after closed commissurotomy if a systolic murmur was present, whereas those without a systolic murmur did not suffer from hemodynamic problems and had satisfactory outcomes. Persistent mitral regurgitation after commissurotomy was recognized as a significant clinical problem that needs to be avoided. This fact probably triggered the surgeons’ desire for a precise intraoperative diagnostic method, and the requirements of such a method caused them to fix on echocardiography as the ideal tool for this function.
    12/2010: pages 3-24;
  • M. Musci · M. Hübler · A. Amiri · M. Pasic · Y. Weng · R. Hetzer
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    ABSTRACT: In the treatment of degenerative severe mitral regurgitation, there is a general consensus and well-accepted class 1 grade A level evidence for preferring mitral valve (MV) repair over MV replacement. If MV repair is feasible, it has been shown to reduce operative mortality and improve long-term survival and functional status in the comparison with MV replacement.
    Mitral Valve Repair, 12/2010: pages 259-271;
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    ABSTRACT: We retrospectively analysed the profile and outcome of surgically treated patients with active infective prosthetic valve endocarditis (PVE) over a period of 22 years. Between May 1986 and December 2008, a total of 1313 patients with active infective endocarditis (AIE) were operated on, 349 (26.6%) of them for PVE. Of these, 77 (22.1%) had to be operated upon due to early PVE (≤60 days, n=55 men, median age: 58 years) and 272 (77.9%) due to late PVE (n=200 men, median age: 63 years). A large proportion of patients were referred to our department with advanced endocarditis and in a condition of cardiac and pulmonary decompensation. A total of 226 (64.8%) patients developed periannular abscess. Operations consisted of 80 aortic valve, 45 mitral valve, 39 double valve and 165 aortic root replacements, 134 of them with a homograft. Perioperative characteristics, probability of survival, freedom from recurrence and predictors for hospital mortality were analysed. Follow-up (maximum: 19.4 years) was completed in 96.3% (total: 1118 patient-years). There was high early and late mortality. Overall in-hospital mortality was 28.4% (99/349). The 30-day, 1-, 5- and 10-year survival for the whole PVE study population was 71.4 ± 2.4%, 58.7 ± 2.7%, 44.5 ± 3% and 31.7 ± 3.5% with no significant differences between the early and late PVE patients: 67 ± 5.4%, 55.9 ± 5.8%, 49.4 ± 6.2% and 29.7 ± 7.6%, compared to 72.4 ± 3%, 60 ± 3%, 43.5 ± 3.3% and 31.1 ± 3.8% (p=0.93). Predictors of early mortality were mechanical support (risk ratio (RR): 4.3), emergency operation (RR: 2.1), preoperative high doses of catecholamines (RR: 1.8), mitral valve replacement (RR: 1.5) and age at operation (RR: 1.1). Freedom from re-operation due to recurrent endocarditis at 10 years was 85.8 ± 5.6% for early PVE compared to 92.1 ± 2.3% for late PVE patients (p=0.17). Staphylococcus aureus (S. aureus) (18.1%) was the most frequent causative micro-organism. Surgery for active infective PVE continues to be challenging. It not only carries a high in-hospital mortality but is also associated with a high long-term mortality risk. Early PVE patients were in a more severe condition than late PVE patients. Preoperative status, complications and co-morbidity of PVE patients strongly predict early outcome. Because of the potential risk of late complications, PVE patients need close clinical follow-up.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 11/2010; 38(5):528-38. DOI:10.1016/j.ejcts.2010.03.019 · 3.30 Impact Factor
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    ABSTRACT: A retrospective analysis was conducted of the early and long-term results of mitral valve repair (MVRep) and mitral valve replacement (MVR) in patients with isolated infective mitral valve endocarditis. Between May 1986 and December 2007, a total of 1,163 patients with active infective endocarditis (AIE) were operated on. Of these patients, 497 showed an endocarditic involvement of the mitral valve. Sixty-one of these patients underwent MVRep and 219 MVR, with 24% cases of prosthetic valve endocarditis (PVE). The patients' perioperative characteristics, cumulative survival, freedom from recurrence and reoperation and independent risk factors for early mortality were analyzed. Follow up (0-21 years) was complete in 96.5% of cases; the total follow up was 348 and 810 patient-years (pt-yr) in the MVRep and MVR groups, respectively. Typically, the MVR patients were significantly older (p < or = 0.001), preoperatively more often intubated (p = 0.008) and in cardiogenic shock (p = 0.045), and more often underwent emergency surgery (p = 0.023). MVRep was associated with a significantly better survival, with 30-day, one-, five- and 10-year survival rates of 90.1 +/- 3.9%, 83.2 +/- 4.8%, 77.0 +/- 5.7% and 60.5 +/- 8.0%, respectively (p = 0.002). Survival after MVR was significantly worse with abscess formation (p = 0.0002) and PVE (p = 0.038). Freedom from reoperation due to reinfection after 10 years was 89.4 +/- 7.0% after MVRep, with early endocarditis recurrence in two patients (3%), and 91.0 +/- 2.5% after MV, with early recurrence in four patients (2%) (p = 0.46). Multivariate analysis identified preoperative ventilation (OR = 6.3), mitral valve abscess formation (OR = 5.3), PVE (OR = 3.1) and age > or = 60 years (OR = 2.8) as independent risk factors for early mortality. Compared to the MVRep group, patients requiring MVR had more advanced endocarditis and were more critically ill. These results suggest that the early outcome might have been improved if patients had been operated on before either heart failure or the development of septic shock. MVRep for AIE showed a low operative mortality and provided satisfactory freedom from recurrent infection and repeat operation. If all infected material could be resected such that the remaining tissue would allow the re-shaping of a competent valve, then MVRep could be performed also in infective endocarditis, in line with the general recommendations for mitral valve surgery.
    The Journal of heart valve disease 03/2010; 19(2):206-14; discussion 215. · 0.75 Impact Factor
  • The Thoracic and Cardiovascular Surgeon 02/2010; 58. DOI:10.1055/s-0029-1246655 · 0.98 Impact Factor
  • The Thoracic and Cardiovascular Surgeon 02/2010; 58. DOI:10.1055/s-0029-1246944 · 0.98 Impact Factor
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    ABSTRACT: Despite improvements in medical care, the incidence of left-sided active infective endocarditis (AIE) has remained unchanged over the past few decades. As shown in a review of 26 publications on a total of almost 3800 patients treated between 1993 and 2003, it is reported to affect a median of 3.6–5.4/100 000 persons per year, increasing in individuals over 65 years old to 15.0/100 000 persons per year, with a male:female ratio of 2:1 [1]. This unchanging incidence may be explained by changes in both the spectrum of causative organisms and in the patients affected [2]. New groups at risk of endocarditis have emerged, for example, the increasingly aging population with heart valve sclerosis, patients with prosthetic valves, those exposed to nosocomial infections, hemodialysis patients, and intravenous drug abusers [3], while chronic rheumatic fever, which was a classic predisposing factor in the preantibiotics era, has become rare in industrialized countries. These developments reflect our experience of continuing high numbers of patients who have to be operated on for AIE each year: between May 1986 and December 2008 a total of 1313 AIE patients were operated on at the Deutsches Herzzentrum Berlin, 72.4% (n=1009) for native endocarditis and 27.6% (n=384) for prosthetic endocarditis (Fig. 1). Fig. 1.Operations for native and prosthetic active infective endocarditis at the Deutsches Herzzentrum Berlin from May 1986 to December 2008
    12/2009: pages 210-222;
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    ABSTRACT: We compared early and long-term results of cryopreserved homograft aortic root replacement in native valve endocarditis or prosthetic valve endocarditis associated with periannular abscess. Between May 1986 and December 2007, 1163 patients with endocarditis were operated upon. Of these, 221 patients (n = 185 men, median age 55 years) had homograft aortic root replacement due to 99 cases of native valve endocarditis (45%) and 122 of prosthetic valve endocarditis (55%). Perinannular abscess developed in 189 patients (86%), and aortoventricular dehiscence in 120 (63.5%) of them. Perioperative characteristics, probability of survival, freedom from recurrence, and reoperation were analyzed. Follow-up (mean 5.2 +/- 0.4 years, maximum 18.4 years) was completed in 96.8% with a total of 1127 patient-years. Overall native valve endocarditis survival at 30 days and 1, 5, and 10 years was 83.8% +/- 3.7%, 76.6% +/- 4.3%, 66.5% +/- 4.9%, and 47.3% +/- 5.6%, respectively, significantly better than for patients with prosthetic valve endocarditis, who had a greater tendency toward abscess formation (P = .029). Thirty-one patients (14.0%) required reoperation either for structural valve deterioration (n = 19, 8.6%), with a greater tendency in patients aged <40 years, or for recurrent endocarditis of the homograft (n = 12, 5.4%). One-year reoperation mortality rate was 16.1% (n = 5). Homograft aortic root replacement in active infective endocarditis with periannular abscess formation shows satisfactory early and long-term results with significantly better survival in native valve endocarditis than prosthetic valve endocarditis. It is associated with a low recurrence rate, although the risk of structural valve deterioration increases over time, especially in young patients, and reoperation remains a challenge. In our institution, the homograft remains the preferred valve substitute in active infective endocarditis with periannular abscess formation.
    The Journal of thoracic and cardiovascular surgery 09/2009; 139(3):665-73. DOI:10.1016/j.jtcvs.2009.07.026 · 4.17 Impact Factor
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    ABSTRACT: We report an unusual case of a pseudocyst in the left ventricular outflow tract in a 58-year-old woman. The cyst was successfully resected by a transatrial approach.
    The Annals of thoracic surgery 02/2008; 85(1):315-7. DOI:10.1016/j.athoracsur.2007.06.047 · 3.85 Impact Factor
  • R Baretti · M Amiri · A Amiri · H Siniawski · R Hetzer
    The Thoracic and Cardiovascular Surgeon 01/2005; 53(S 01). DOI:10.1055/s-2005-862028 · 0.98 Impact Factor