Mitral valve repair versus replacement with extensive annular calcification: a systematic review and meta-analysis

Background: Mitral annular calcification (MAC) represents an important risk factor in mitral valve (MV) surgery. Despite several procedures have been described, no surgical treatment of choice has been yet established. Materials and Methods: A systematic review of the literature and meta-analysis on patients undergoing MV surgery associated to MAC was performed. The meta-analysis primary endpoints were 30-day mortality and late overall and cardiac-related mortality. Secondary endpoints were early reintervention, re-exploration for bleeding, postoperative pacemaker implantation, cerebrovascular accident, atrioventricular groove rupture, acute myocardial infarction and late recurrences of mitral regurgitation (MR) or paravalvular leak and reintervention. Primary and secondary endpoints were also evaluated in the subgroup analysis between MV repair and replacement surgery. Meta-regression was used to analyze the influence of decalcification and annular reconstruction on endpoints. Results: Among 1429 papers, 25 papers studying 1327 patients were included. In the pooled analysis, the 30-day mortality event rate was 2.89% (95%Confidence Interval [CI], 1.48%-5.57%) and 7.72% (95%CI, 2.95%-18.71%) for MV repair and replacement respectively. At mid-term follow-up, MV repair revealed a significantly lower incidence rate (IR) of death compared to MV replacement (p=0.043), with a trend of higher reoperation IR compared to replacement (p=0.051) and a trend of higher recurrent MR2+ in MV repair (p=0.071). Annular reconstruction was associated with a significant increase in re-exploration for bleeding at univariate analysis, but not at the multivariate meta-regression. Conclusions: The current meta-analysis suggests that MV repair in MAC patients may provide better short and mid-term survival outcomes when compared to replacement.

A rare cause of culture negative bioprosthetic valve endocarditis: a case report of Aggregatibacter aphrophilus infection

Background The prevalence of culture negative infective endocarditis (IEC) is reported as 2–7% though this figure may be as high as 70% in developing countries.1 This higher rate will, at least in part, be due to reduced diagnostic facilities though some data suggests higher rates even when appropriate cultures were taken. The frequency is significantly elevated in patients who have already been exposed to antibiotics prior to blood cultures.1,2 A rare cause of culture negative IEC is the HACEK group of organisms that are normal habitants of the oropharyngeal flora and account for 1–3% of native valve endocarditis.3Aggregatibacter aphrophilus (A. aphrophilus) is a member of the HACEK group of organisms. Case summary A 32-year-old gentleman with a previous bioprosthetic aortic valve presented with a 1-week history of diarrhoea, vomiting, malaise, and weight loss. He was awaiting redo surgery for stenosis of the bioprosthesis, which had been inserted aged 17 for aortic stenosis secondary to a bicuspid valve. The initial blood tests revealed liver and renal impairment with anaemia. A transoesophageal echocardiogram demonstrated a complex cavitating aortic root abscess, complicated by perforation into the right ventricle. He underwent emergency redo surgery requiring debridement of the aortic abscess, insertion of a mechanical aortic prosthesis (St Jude Medical, USA), annular reconstruction and graft replacement of the ascending aorta. Despite antibiotic therapy, he remained septic with negative blood and tissue cultures. Bacterial 16S rRNA gene sequencing confirmed A. aphrophilus infection, for which intravenous ceftriaxone was initiated. This was subsequently changed to ciprofloxacin due to neutropenia. The patient self-discharged from the hospital during the third week of antibiotic therapy. One week later, he was re-admitted with fever, night sweats, and dyspnoea. Transthoracic echocardiogram revealed a large recurrent aortic abscess cavity around the aortic annulus fistulating into the right heart chambers; this was confirmed by a computed tomography scan. There was dehiscence of the patch repair. Emergency redo aortic root replacement (25 mm mechanical valve conduit, ATS Medical, USA) and annular reconstruction was performed with venoarterial extracorporeal membrane oxygenation (VA-ECMO) support. VA-ECMO was weaned after 3 days. The patient completed a full course of intravenous meropenem and ciprofloxacin and made a good recovery. Discussion IEC with oropharyngeal HACEK organisms is rare and difficult to diagnose, due to negative blood culture results. The broad-range polymerase chain reaction and gene sequencing with comparison to the DNA database is useful in these circumstances. This case demonstrates the importance of the 16S rRNA gene sequencing for HACEK infection diagnosis and appropriate antibiotic treatment.

Taming of the Tiger: A Novel Technique to Deal With Mitral Annular Calcification —A Case Series

Background: Mitral valve surgery can be challenging for patients with mitral annular calcification (MAC). The prevalence of MAC in patients who undergo mitral valve replacement is 19.9%. The treatment options for MAC include complete decalcification and annular reconstruction with valve repair/replacement or performing a surgical valve repair or replacement without decalcification, accepting the risk of paravalvular leak. We describe three cases of mitral valve prolapse with posterior annular calcification, which were repaired using a unique technique that does not require decalcification. Case reports: The mitral annular calcification was heavy and involved most of the posterior annulus just sparing the commissures in all the three cases. Leaflet prolapse was dealt with by using neochordae, closing any clefts, and leaflet plication. Since the MAC ring was not complete and there was chance of further dilatation of the annulus, a partial annuloplasty was done using a PTFE felt (cut as strip). There was trivial to no mitral regurgitation with this technique in the immediate postoperative and five-year follow-up period echocardiography in all the three cases. Conclusion: This technique can benefit the major subset of pure mitral valve regurgitant lesions associated with MAC, which is limited to the posterior annulus.

Cardiac Tamponade following Mitral Valve Replacement for Active Infective Endocarditis with Ring Abscess

Periannular extension and abscess formation are rare but deadly complications of infective endocarditis (IE) with high mortality. Multimodality cardiac imaging, invasive and noninvasive, is needed to accurately define the extent of the disease. Debridement, reconstruction, and valve replacement, often performed in an emergent setting, remain the treatment of choice. Here we present a case of severe IE in a 29-year-old intravenous drug user who after undergoing debridement of the abscess, annular reconstruction, and mitral valve replacement (MVR) presented with recurrence of shortness of breath and pedal edema. Transthoracic echocardiogram (TTE) showed a6.2×5.5 cm cavity, posterior to and communicating with the left ventricle through a 3 cm wide fistulous opening, in proximity of the reconstructed mitral annulus. The patient underwent a redo MVR with patch closure of the fistulous opening, with good clinical outcome. This case highlights the classic TTE findings and the necessity for close follow-up in the perioperative period in patients undergoing surgery for periannular extension of infection. A cardiac magnetic resonance imaging can be considered, preoperatively, in such cases to identify the extent of myocardial involvement and surgical planning.