Endocarditis Risk, Morbidity in TAVR Rival Valve Surgery

September 19, 2016

QUEBEC CITY, QC — One in 80 patients undergoing transcatheter aortic-valve replacement (TAVR) developed endocarditis, typically within 5 months, in a     global registry study published September 13, 2016 in the Journal of the American Medical Association[1]. Moreover, of the patients who developed     endocarditis, 36% died during hospitalization for this and 67% died within 2 years.

Importantly, the study identified that compared with TAVR patients who did not develop this complication, those who did were younger (mean age 79 vs 82) and     more likely to be male (62% vs 50%), have type 2 diabetes (42% vs 30%), and have moderate to severe regurgitation (22% vs 15%).

The most frequent causative organisms were Enterococci (25% of cases), unlike in previous reports, closely followed by    Staphylococcus aureus (23%).

Thus, although TAVR is less invasive than surgical valve replacement, it carries a similar risk of endocarditis, Dr Ander Regueiro (Laval University,     Quebec City, QC) and colleagues report.

"This study confirms the high rate of morbidity and mortality of infective endocarditis after TAVR and provides novel information about the timing,     causative organisms, and predictive factors of infective endocarditis in this particular population," they write. "This information may help the clinicians     identify patients at higher risk and aid in implementing appropriate preventive measures."

Little Known About Endocarditis After TAVR

Infective endocarditis following surgical valve replacement occurs in 1% to 6% of patients, Regueiro and colleagues write. However, less is known about     rates of endocarditis after TAVR.

To investigate clinical characteristics and outcomes of patients undergoing TAVR who develop endocarditis, the researchers analyzed data from the     Infectious Endocarditis after TAVR International Registry, from 47 sites in Europe, North America, and South America.

Of 20,006 registry patients who underwent TAVR between June 2005 and October 2015, 250 patients (1.1%) were diagnosed with infective endocarditis.

The patients had a mean age of 80 with a high prevalence of comorbidities such as type 2 diabetes, chronic renal failure, and chronic obstructive pulmonary     disease (COPD).

Patients had received antibiotic prophylaxis mostly with β-lactam alone (78%) and less often with vancomycin alone (6%).

TAVR was performed in a cath lab in 43% of cases and in an operating or hybrid operating room in 57% of the cases.

Operators implanted a CoreValve self-expandable valve in 46% of cases and an Edwards balloon-expandable valve in 52% of cases.

In 53% of cases, the endocarditis was related to recent healthcare, including IV therapy, wound care, nursing care at home, hemodialysis, chemotherapy, a     recent 2-day hospital admission, or living in a nursing home or long-term-care facility.

The most common symptoms of endocarditis were fever (80%) and acute heart failure (40%).

The valve was surgically explanted during endocarditis hospitalization in 11% of patients. But most patients were treated solely with antibiotic therapy:     β-lactams alone (15%) or with another antibiotic (50%) or vancomycin alone or in combination (21%).

Higher-Than-Expected Endocarditis Rates, Enterococci Infections

The rate of infective endocarditis within 60 days of TAVR was 29% of cases, which was higher than the 14% rate reported by the    International Collaboration on Endocarditis (ICE) Prospective Cohort Study (PCS), possibly     due to the higher risk profile of the patients or the greater instrumentation used in TAVR, "suggesting the need for a more cautious approach by avoiding     unnecessary invasive examinations and reinforcing the importance of maintaining aseptic conditions during any invasive procedure," Regueiro and colleagues     write.

In addition to Enterococci and S aureus, the other causative organisms included coagulase-negative Staphylococcus (17%) and    Viridans streptococci (7%).

The higher rate of endocarditis caused by enterococci may be related to older age, chronic disease, aortic-valve calcification, or femoral access (since     these bacteria are a frequent groin contaminant), and this should help guide antibiotic choice while waiting for culture results in patients with suspected     endocarditis, according to the researchers.

Moreover, "β-lactam antibiotics were used as antibiotic prophylaxis during TAVR procedures in most patients, but their efficacy in preventing enterococci     infections is limited; glycopeptides and aminoglycosides would seem a better option in such cases," they suggest.

The 2-year mortality after hospitalization for endocarditis (67%) "seems higher" than that observed in after surgical valve implantation (27% to 61%) or reported in TAVR trials (22% in the US pivotal trial for the self-expanding valve and 34% in the [PARTNER] trial)," the researchers note, which "highlights the poor     prognosis of patients with infective endocarditis after TAVR."

Only 10% of the patients had the valve surgically explanted—likely due to the high or prohibitive risk of surgery in these patients or technical     difficulties in removing a stent adherent to the aorta—but valve explantation was not tied to improved survival, Regueiro and colleagues note. Thus, further     study is needed to address surgical explantation in this "challenging group of patients."

        Dr Regueiro was supported by a grant from the Fundacion Alfonso Martin Escudero, Madrid, Spain. Disclosures for the coauthors are listed in the         article.    

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