Staphylococcus lugdunensis infective endocarditis with perforation of the sinus of Valsalva: a case report

Background

Staphylococcus lugdunensis endocarditis is a rare but fulminant disease.

Case summary

A 74-year-old female with a history of asymptomatic severe aortic valve stenosis and permanent atrial fibrillation presented with acute onset of fever (39.0°C). Electrocardiogram showed diffuse ST-segment elevation. She was hospitalized for further analysis. All blood cultures were positive for Staphylococcus lugdunensis and antibiotic treatment was started. Transthoracic echocardiography (TTE) showed known aortic valve stenosis without clear signs of endocarditis. The following day, a transoesophageal echocardiogram (TEE) showed a new moderate aortic valve regurgitation, new pericardial effusion (PE), and a thickened sinus of Valsalva (SOV) consistent with endocarditis with paravalvular involvement. Positron emission tomography-computed tomography was consistent with aortic valve endocarditis with paravalvular expansion. The patient was transferred to a tertiary referral centre for surgical treatment. On admission, patient was in shock and a second TTE revealed a new systolic and diastolic flow through the SOV to the right ventricle indicating SOV perforation. Additionally, there was flow in the PE suggestive of perforation of one of the cardiac chambers or large vessels. Emergent surgery showed extended infection with SOV perforation and a large perforation of the right ventricle. Ultimately, patient died during the operation because of extensive infection and refractory shock.

Conclusion

Staphylococcus lugdunensis endocarditis is a severe disease with poor response to conventional anti-microbial treatment, destructive complications requiring surgery, and has a high mortality risk.

Antithrombotic therapy in patients undergoing TAVI: an overview of Dutch hospitals

Purpose

To assess current antithrombotic treatment strategies in the Netherlands in patients undergoing transcatheter aortic valve implantation (TAVI).

Methods

For every Dutch hospital performing TAVI (n = 14) an interventional cardiologist experienced in performing TAVI was interviewed concerning heparin, aspirin, thienopyridine and oral anticoagulation treatment in patients undergoing TAVI.

Results

The response rate was 100 %. In every centre, a protocol for antithrombotic treatment after TAVI was available. Aspirin was prescribed in all centres, concomitant clopidogrel was prescribed 13 of the 14 centres. Duration of concomitant clopidogrel was 3 months in over two-thirds of cases. In 2 centres, duration of concomitant clopidogrel was based upon type of prosthesis: 6 months versus 3 months for supra-annular and intra-annular prostheses, respectively.

Conclusions

Leaning on a small basis of evidence and recommendations, the antithrombotic policy for patients undergoing TAVI is highly variable in the Netherlands. As a standardised regimen might further reduce haemorrhagic complications, large randomised clinical trials may help to establish the most appropriate approach.

Electronic supplementary material

The online version of this article (doi:10.1007/s12471-013-0496-6) contains supplementary material, which is available to authorized users.

Can minimized cardiopulmonary bypass systems be safer?

Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit.

Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the ‘Better Bladder’ (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity.

Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%.

In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing.