Daniel Z. Uslan

Risk Factor Analysis of Permanent Pacemaker Infection

Background. Several host- and procedure-related factors have been reported to increase the risk of permanent pacemaker (PPM) infection on the basis of descriptive analyses of case series. The purpose of this study is to assess the risk factors for PPM infection using case-control study methods.Methods. All patients who had a PPM implanted at our institution from January 1991 to December 2003 were retrospectively reviewed. Each patient who experienced a PPM infection was matched with 2 control subjects by age, sex, year of implantation, and duration of follow-up. Univariate and multivariable analyses were performed to identify significant risk factors for PPM infection.Results. Twenty-nine case patients and 58 control subjects met inclusion criteria. The majority (83%) of case patients presented with a pocket infection; a minority (10%) had PPM-related endocarditis. Staphylococcus species (69%) were the most common pathogens. On univariate analysis, previous PPM infection, malignancy, long-term corticosteroid use, multiple device revisions, a permanent central venous catheter, the presence of >2 pacing leads, and a lack of antibiotic prophylaxis at the time of PPM placement were associated with an increased risk of PPM infection. A multivariable logistic regression model identified long-term corticosteroid use (odds ratio [OR], 13.90; 95% confidence interval [CI], 1.27-151.7; P=.03) and the presence of >2 pacing leads versus 2 leads (OR, 5.41; 95% CI, 1.44-20.29; P=.01) as independent risk factors for PPM infection. In contrast, use of antibiotic prophylaxis prior to PPM implantation had a protective effect (OR, 0.087; 95% CI, 0.016-0.48; P=.005).Conclusions. These findings should assist clinicians in identifying patients who are at increased risk of PPM infection, as well as in developing strategies to minimize the modifiable risks.

Infective Endocarditis Complicating Permanent Pacemaker and Implantable Cardioverter-Defibrillator Infection

OBJECTIVEnTo describe management of patients with permanent pacemaker (PPM)- and implantable cardioverter-defibrillator (ICD)-related endocarditis.nnnPATIENTS AND METHODSnWe retrospectively reviewed all cases of infection involving PPMs and ICDs among patients presenting to Mayo Clinics site in Rochester, MN, between January 1, 1991, and December 31, 2003. Cardiac device-related infective endocarditis (CDIE) was defined as the presence of both vegetation on a device lead or valve and clinical or microbiological evidence of CDIE. Of 189 patients with PPM or ICD infection who were admitted during the study period, 44 met the case definition for CDIE (33 PPM, 11 ICD).nnnRESULTSnThe mean +/- SD age of patients was 67 +/- 14 years. Staphylococci (36 [82%]) were the most commonly isolated pathogens. Nearly all patients (43 [98%]) were treated with a combined approach of complete hardware removal and parenteral antibiotics. The median duration of antibiotic treatment after infected device explantation was 28 days (interquartile range, 19-42 days). Device leads were removed percutaneously in 34 cases (77%); only 7 cases (16%) required surgical lead extraction. Percutaneous extraction was uncomplicated in 15 patients with lead vegetation greater than 10 mm in diameter. Six patients (14%) died during hospitalization. Twenty-seven (96%) of 28 patients remained infection free at their last visit (median follow-up, 183 days; intraquartile range, 36-628 days).nnnCONCLUSIONnPrompt hardware removal and prolonged parenteral antibiotic administration decrease mortality among patients with CDIE. The presence of a large (> 10 mm in diameter) vegetation on a lead is not a contraindication for percutaneous lead extraction.

Temporal Trends in Permanent Pacemaker Implantation: A Population-Based Study

BACKGROUNDnLimited data exist regarding temporal trends in permanent pacemaker (PPM) implantation. To describe trends in incidence and comorbidities of PPM recipients, we conducted a retrospective population-based cohort study over a 30-year period.nnnMETHODSnAll 1291 adult residents of Olmsted County, Minnesota, undergoing PPM implantation between 1975 and 2004 were included in the study. Trends in PPM implantation incidence, pacing mode and indication, and comorbidities (via Charlson Comorbidity Index [CCI]) were assessed through the Rochester Epidemiology Project. Permanent pacemaker recipients were compared with age- and sex-matched PPM-free controls from the population.nnnRESULTSnAdjusted implantation incidence rates increased from 36.6 per 100,000 person-years during 1975 to 1979 to 99 per 100,000 person-years during 2000 to 2004 (P < .0001). After adjusting for age (hazard ratio [HR] 1.06 per year), male sex (HR 1.28), and implant year (HR 0.98), the HR for death among PPM recipients by CCI quartiles was 1.0, 1.79, 2.29, and 3.91 for CCI of 0 to 1 (reference), 2 to 3, 4 to 6, and > or = 7, respectively (P < .0001). Overall, PPM recipients had higher CCI than the population-based controls (P = .04), with higher mean CCI noted since 1990. Mean age-adjusted CCI increased from 3.15 to 4.60 among the cases (P < .0001) and from 3.06 to 3.54 among the age- and sex-matched controls (P = .047).nnnCONCLUSIONSnThere have been significant increases in incidence of PPM implantation over 30 years, and PPM recipients have had an age-independent increase in comorbidities relative to the underlying population, especially over the past 15 years.

Frequency of Permanent Pacemaker or Implantable Cardioverter-Defibrillator Infection in Patients with Gram-Negative Bacteremia

BACKGROUNDnDespite the frequent occurrence of bacteremia due to gram-negative organisms in patients with underlying permanent pacemakers (PPMs) or implantable cardioverter defibrillators (ICDs), the outcome and treatment of these patients has received scant attention. In patients with PPMs or ICDs who have Staphylococcus aureus bacteremia, 45% have PPM/ICD infection.nnnMETHODSnWe conducted a retrospective cohort study over a 7-year period to assess the clinical features and frequency of PPM/ICD infection in patients with gram-negative bacteremia, as well as the incidence of relapse in patients for whom the device was not removed.nnnRESULTSnForty-nine patients were included in the study; 3 (6%) had either definite (2 patients) or possible (1 patient) PPM/ICD infection. Both patients with definite PPM/ICD infection had clear infection of the generator pocket. None of the other patients with alternate sources of bacteremia developed PPM/ICD infection. Thirty-four patients with retained PPM/ICD were observed for >12 weeks (median time, 759 days), and 2 (6%) developed relapsing bacteremia, although they each had alternative sources of relapse.nnnCONCLUSIONSnIn sharp contrast to S. aureus infection, PPM/ICD infection in patients with gram-negative bacteremia was rare, and no patients appeared to have secondary PPM/ICD infection due to hematogenous seeding of the system. Despite infrequent system removal in these patients, relapsing bacteremia among patients who survived initial bacteremia was rarely seen. If secondary PPM/ICD infection occurs in patients with gram-negative bacteremia, it is either uncommon or it is cured with antimicrobial therapy despite device retention.

Age and gender trends in implantable cardioverter defibrillator utilization: A population based study

IntroductionImplantable cardioverter-defibrillators improve mortality in selected high risk patients, yet population based data regarding utilization of these devices, particularly in the elderly, are limited.MethodsTo address this, we reviewed all ICD implantations performed in Olmsted County, MN, a geographically defined population, between December 1989 and December 2004.ResultsThe study population comprised 179 patients (147 male, 82%, mean age 65u2009±u200914xa0years). Baseline ejection fraction and creatinine were 35%u2009±u200916% and 1.38u2009±u20091.08xa0mg/dl, respectively. Over the study period, the incidence of congestive heart failure in patients undergoing ICD implantation and referrals for primary prevention ICDs increased, while baseline ejection fraction and etiology of cardiomyopathy remained unchanged. The incidence of ICD implantations increased significantly in the elderly (pu2009<u20090.001) and especially in male patients when compared to female patients (pu2009<u20090.001).ConclusionsAge of patients undergoing ICD implantation is increasing. However, fewer females compared to males are undergoing ICD implantation, suggesting a gender bias in ICD therapy and utilization.

Melarsoprol-associated multifocal inflammatory CNS illness in African trypanosomiasis

A 62-year-old woman was evaluated for an undiagnosed febrile illness. Four weeks after returning from an African safari to Kenya and Tanzania, she became symptomatic with intermittent high-grade fever that persisted despite a trial of quinine and antimicrobials (levofloxacin, azithromycin, metronidazole, doxycycline, and vancomycin). The fever was accompanied by an erythematous abdominal rash. She recalled an insect bite on her left foot while in Africa. East African trypanosomiasis was diagnosed based on the presence of Trypanosoma brucei rhodesiense on a peripheral smear. She was given one dose of IV pentamidine. Suramin was procured from the Centers for Disease Control and administered. CSF showed increased white cell count (164 cells/μL) and proteins (191 mg/dL). Though the patient did not have neurologic symptoms, because of CSF evidence of CNS involvement, therapy was changed to IV melarsoprol (week 1: 108 mg daily for 3 days, week 2: 144 mg daily for 3 days, week 3: 216 mg daily for 3 days). Melarsoprol was administered with prednisone to prevent encephalopathy. Clinical improvement was associated with resolution of the pyrexia, progressive decrease in the CSF cell count, clearance of parasitemia on serial blood smears, and continued absence of the parasite on CSF …

Postexposure Chemoprophylaxis for Occupational Exposure to Human Immunodeficiency Virus in Traveling Health Care Workers

BACKGROUNDnThere has been little research on the use of human immunodeficiency virus (HIV) postexposure prophylaxis (PEP) for occupational exposure in traveling health care workers (HCWs). Although PEP is the standard of care for occupational exposure to HIV in the United States, in third-world countries such medications are often unavailable and risks to the HCW may be higher. The aims of this study were to assess the incidence and types of blood and body fluid exposure and subsequent use of PEP in traveling HCWs seen at a large travel clinic prior to travel.nnnMETHODSnTo determine the utility of PEP, we retrospectively evaluated all HCWs presenting for counseling prior to travel for health care delivery. All employees who were seen at the Mayo Travel and Tropical Medicine Clinic from 1999 until July 2002 were included. Analysis was conducted via a chart review as well as an approved questionnaire mailed to all employees still at the Mayo Clinic.nnnRESULTSnEighty-six HCWs were included in the analysis, and 58 responded to the questionnaire. Of the 86 HCWs reviewed, 55 (64%) were determined to be at high risk for occupational exposure to HIV. Seventy-eight percent of the high-risk HCWs were documented to have been counseled about needlestick avoidance, and 55% brought PEP with them. In the 58 HCWs who returned the questionnaire, there were no reported deep needlesticks. One of the 39 high-risk HCWs who returned the questionnaire (2.6%) had a superficial needle exposure, but the source patient had pretested negative for HIV and therefore the HCW did not use PEP. Nine of the 39 (23%) had a blood splash onto intact skin, and one of these involved a large volume. This source patient also had pretested negative for HIV. None of the HCWs exposed to blood splash took PEP. Two HCWs (5.1%) at high risk had an exposure that would have required PEP if the source patient had not been pretested.nnnCONCLUSIONSnNeedlestick exposure and HIV PEP counseling is important for HCWs traveling for health care delivery. Exposure risks appear low but high enough to warrant supplying high-risk HCWs with PEP. HCWs are able to use the recommendations appropriately. Pretesting of surgical patients decreases the likelihood of starting PEP. Carrying a common supply of PEP for a larger group can decrease the cost of PEP.

African tick-bite fever.

A 62-year-old man presented to our institution with a 1week history of a nonpruritic rash on his left leg, lowgrade fever, and tender inguinal adenopathy. He had traveled to the African countries of Malawi and Zambia for sight-seeing and a safari during the month before onset of symptoms. He denied any insect exposure but used no specific topical prophylaxis. On examination, the patient appeared well; his temperature was 36.8°C. He had tender left inguinal lymphadenopathy. An approximately 1-cm black eschar was evident just below his left knee (Figure) along with a large area of erythematous skin and a petechial nonblanching rash. There was associated lymphangitic streaking extending up toward the inguinal area and pronounced unilateral pitting edema. The adenopathy resolved within 2 days of initiation of doxycycline therapy. After approximately 1 week, the rash began to fade, and the lymphedema resolved. A serologic test for Rocky Mountain spotted fever (RMSF) was positive at 1:512. Because RMSF is not endemic to Africa, other specific rickettsial serologic tests were requested from a research laboratory. These revealed an initial Rickettsia africae IgG of 1:32 with an IgM of 1:8; analysis 1 month later revealed an IgG of 1:256. Other rickettsial serologic tests were negative. African tick-bite fever (R africae) is an increasingly common and appreciated cause of illness in travelers returning from Africa. In a recent study, 27% of patients returning from sub-Saharan Africa with fever were found to have R africae infection. The infection is spread by the Amblyomma tick, a notoriously aggressive tick that is associated with wild game but may be found on vegetation. Common clinical characteristics are fever, headache, myalgias, lymphadenitis, and an inoculation eschar with cutaneous rash—the classic tache noire. No readily available serologic diagnosis exists except in research laboratories, although a serologic test for RMSF will occasionally be positive. The infection is usually self-limited but can be treated with oral doxycycline.