Pre-operative risk factors for driveline infection in left ventricular-assist device patients.

AIMS: Implantation of left ventricular-assist devices (LVAD) to treat end-stage heart failure is of increasing relevance due to donor shortage. Infections of the driveline are common adverse events. LVAD infections can lead to high urgency listings for transplantation. However, transplantation in patients with infection leads to worse post-transplantation outcomes. This study aims to evaluate specific risk factors for driveline infections at the time of implantation. METHODS AND RESULTS: Four hundred forty-one patients receiving either Heartmate II or Heartware system from August 2009 to October 2013 were assessed. An expert committee sorted patients into four different groups concerning the likeliness of infection. Twenty-eight (6%) of discussed infection cases were judged as secured, 33 (7%) as likely, 18 (4%) as possible, and 20 (4%) as unlikely. The remaining 342 (78%) subjects showed either no signs of infection at all times (329 [75%]) or developed signs of infection in a second observation period within 1 year after ending of the first observation period (13 [3%]). For a better discriminatory power, cases of secured and likely infections were tested against the group with no infection at all times in a Cox proportional hazard model. Among all variables tested by univariate analysis (significance level P < 0.15), only age (P = 0.07), LVAD-type (P = 0.12), need for another thoracic operation (P = 0.02), and serum creatinine value (P = 0.02) reached statistical significance. These were subsequently subjected to multivariate analysis to calculate the cumulative risk of developing a drive infection. The multivariate analysis showed that of all the potential risk factors tested, only the necessity of re-thoracotomy or secondary thoracic closure had a significant, protective effect (hazard ratio [95% CI] = 0.45 [0.21-0.95]; P = 0.04). CONCLUSION: This single-centre cohort study shows that driveline infections are common adverse events. The duration of support represents the major risk factor for LVAD driveline infections.

Culture-negative infectious endocarditis caused by Bartonella spp.: 2 case reports and a review of the literature.

Bartonella spp. are rare pathogens in humans and were recently recognized as important causative agents of culture-negative endocarditis. Here, we describe the 1st 2 documented cases of culture-negative endocarditis due to Bartonella henselae and Bartonella quintana encountered in a single hospital in Germany. Infection of the heart valve tissue was detected by broad-range polymerase chain reaction (PCR) and further confirmed by serologic testing. In particular, acute B. henselae infection with an impressive bacterial colonization of the infected cardiac valve was illustrated by transmission electron microscopy. B. henselae was further characterized by PCR assays targeting genotype-specific regions. Disease progression was initially monitored over the entire infection episode through inflammatory markers. In addition, a short overview of published detailed cases of Bartonella endocarditis in Europe within the last 7 years is given.