Patients with Infectious Endocarditis and Drug Dependence Have Worse Clinical Outcomes after Valvular Surgery

Association of Intravenous Drug Use and Length of Stay Following Infective Endocarditis

INTRODUCTION

Intravenous drug use (IVDU) and associated infective endocarditis (IE) has been on the rise in the US since the beginning of the opioid epidemic. IVDU-IE has high morbidity and mortality, and treatment can be lengthy. We aim to quantify the association between IVDU and length of stay (LOS) in IE patients.

METHODS

The National Inpatient Sample database was used to identify IE patients, which was then stratified into IVDU-IE and non-IVDU-IE groups. Weighted values of hospitalizations were used to generate national estimates. Multivariable linear and logistic regression analyses were applied to estimate the effects of IVDU on LOS.

RESULTS

We identified 1,114,257 adult IE patients, among which 123,409 (11.1%) were IVDU-IE. Compared to non-IVDU-IE patients, IVDU-IE patients were younger, had fewer comorbidities, and had an overall longer LOS (median [interquartile range]: 10 [5-20] versus 7 [4-13] d, P < 0.001), with a greater percentage of patients with a LOS longer than 30 d (13.7% versus 5.7%, P < 0.001). After adjusting for multiple demographic and clinical factors, IVDU was independently associated with a 1.25-d increase in LOS (beta-coefficient = 1.25, 95% confidence interval [CI]: 0.95-1.54, P < 0.001) and 35% higher odds of being hospitalized for more than 30 d (odds ratio = 1.35, 95% CI: 1.27-1.44, P < 0.001).

CONCLUSIONS

Among IE patients, being IVDU has associated with a longer LOS and a higher risk of prolonged hospital stay. Steps toward the prevention of IE in the IVDU population should be taken to avoid an undue burden on the healthcare system.

Effect of Publicly Reported Aortic Valve Surgery Outcomes on Valve Surgery in Injection Drug- and Non-Injection Drug-Associated Endocarditis

BACKGROUND

Injection drug use-associated infective endocarditis (IDU-IE) is rising and valve surgery is frequently indicated. The effect of initiating public outcomes reporting for aortic valve surgery on rates of valve surgery and in-hospital mortality for endocarditis is not known.

METHODS

For an interrupted time series analysis, we used data from the National Inpatient Sample, a representative sample of United States inpatient hospitalizations, from January 2010 to September 2015. We included individuals aged 18-65 with an International Classification of Diseases, Ninth Revision (ICD-9) diagnosis of endocarditis. We defined IDU-IE using a validated combination of ICD-9 codes. We used segmented logistic regression to assess for changes in valve replacement and in-hospital mortality rates after the public reporting initiation in January 2013.

RESULTS

We identified 7322 hospitalizations for IDU-IE and 23 997 for non-IDU-IE in the sample, representing 36 452 national IDU-IE admissions and 119 316 non-IDU admissions, respectively. Following the implementation of public reporting in 2013, relative to baseline trends, the odds of valve replacement decreased by 4.0% per quarter (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.93-0.99), with no difference by IDU status. The odds of an in-patient death decreased by 2.0% per quarter for both IDU-IE and non-IDU-IE cases following reporting (OR 0.98, 95% CI 0.97-0.99).

CONCLUSIONS

Initiating public reporting was associated with a significant decrease in valve surgery for all IE cases, regardless of IDU status, and a reduction in-hospital mortality for patients with IE. Patients with IE may have less access to surgery as a consequence of public reporting. To understand how reduced valve surgery impacts overall mortality, future studies should examine the postdischarge mortality rate.

Impact of opioid use disorders on outcomes and readmission following cardiac operations

OBJECTIVE

While opioid use disorder (OUD) has been previously associated with increased morbidity and resource use in cardiac operations, its impact on readmissions is understudied.

METHODS

Patients undergoing coronary artery bypass grafting and valve repair or replacement, excluding infective endocarditis, were identified in the 2010-16 Nationwide Readmissions Database. Using International Classification of Diseases 9/10, we tabulated OUD and other characteristics. Multivariable regression was used to adjust for differences.

RESULTS

Of an estimated 1 978 276 patients who had cardiac surgery, 5707 (0.3%) had OUD. During the study period, the prevalence of OUD increased threefold (0.15% in 2010 vs 0.53% in 2016, parametric trend<0.001). Patients with OUD were more likely to be younger (54.0 vs 66.0 years, p<0.001), insured by Medicaid (28.2 vs 6.2%, p<0.001) and of the lowest income quartile (33.6 vs 27.1%, p<0.001). After multivariable adjustment, OUD was associated with decreased mortality (1.5 vs 2.7%, p=0.001). Although these patients had similar rates of overall complications (36.1 vs 35.1%, p=0.363), they had increased thromboembolic (1.3 vs 0.8%, p<0.001) and infectious (4.1 vs 2.8%, p<0.001) events, as well as readmission at 30 days (19.0 vs 13.2%, p<0.001). While patients with OUD had similar hospitalisation costs ($50 766 vs $50 759, p=0.994), they did have longer hospitalisations (11.4 vs 10.3 days, p<0.001).

CONCLUSION

The prevalence of OUD among cardiac surgical patients has steeply increased over the past decade. Although the presence of OUD was not associated with excess mortality at index hospitalisation, it was predictive of 30-day readmission. Increased attention to predischarge interventions and care coordination may improve outcomes in this population.

Drug Use and Postoperative Mortality Following Valve Surgery for Infective Endocarditis: A Systematic Review and Meta-analysis

BACKGROUND

Infective endocarditis (IE) often requires surgical intervention. An increasingly common cause of IE is injection drug use (IDU-IE). There is conflicting evidence on whether postoperative mortality differs between people with IDU-IE and people with IE from etiologies other than injection drug use (non-IDU-IE). In this manuscript, we compare short-term postoperative mortality in IDU-IE vs non-IDU-IE through systematic review and meta-analysis.

METHODS

The review was conducted according to the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Publication databases were queried for key terms included in articles up to September 2017. Randomized controlled trials, prospective cohorts, or retrospective cohorts that reported on 30-day mortality or in-hospital/operative mortality following valve surgery and that compared outcomes between IDU-IE and non-IDU-IE were included.

RESULTS

Thirteen studies with 1593 patients (n = 341 [21.4%] IDU-IE) were included in the meta-analysis. IDU-IE patients more frequently had tricuspid valve infection, Staphylococcus infection, and heart failure before surgery. Meta-analysis revealed no statistically significant difference in 30-day postsurgical mortality or in-hospital mortality between the 2 groups.

CONCLUSIONS

Despite differing preoperative clinical characteristics, early postoperative mortality does not differ between IDU-IE and non-IDU-IE patients who undergo valve surgery. Future research on long-term outcomes following valve replacement is needed to identify opportunities for improved healthcare delivery with IDU-IE.

Epidemiology, Microbiology, and Clinical Outcomes Among Patients With Intravenous Drug Use-Associated Infective Endocarditis in New Brunswick

BACKGROUND

Within the context of Canada's opioid crisis, medical complications associated with intravenous drug use (IVDU) are increasing. Infective endocarditis (IE) is a serious complication of IVDU, and understanding the characteristics of these patients could aid health systems, clinicians, and patients in the optimization of treatment and prevention of IVDU-IE.

METHODS

At a tertiary care hospital in southern New Brunswick, we conducted a retrospective chart review to identify patients with IVDU-IE admitted between January 1, 2013, and December 31, 2017. We collected data related to the epidemiology, microbiology, clinical manifestations, echocardiography, complications during hospital admission, and outcomes.

RESULTS

Forty-two cases of IVDU-IE met inclusion criteria. The rate of IVDU-IE increased from 2.28 per 100,000 population in 2014 to 4.00 in 2017, which, although not statistically significant, reflects patterns in other jurisdictions. Most patients (72.4%) were male, and the mean age was 38.3 (±11.5) years. Most patients (79.3%) injected opioids. The most common clinical sign was fever (90.5%), and Staphylococcus aureus (61.9%) was the most common microorganism. The tricuspid valve was most commonly infected (58.5%), 50% of cases had heart failure as a complication during admission, and 45.2% of cases required valve replacement or repair. The 2-year survival rate after admission for initial IVDU-IE episode was 62.0% (95% confidence interval: 36.5-79.7).

CONCLUSION

IVDU-IE is common in New Brunswick and may be increasing. Despite the relatively young age of this patient population, IVDU-IE is associated with significant morbidity and mortality. Expanding effective harm reduction and addiction treatment strategies for this cohort is recommended.

Intravenous drug use history is not associated with poorer outcomes after arteriovenous access creation

OBJECTIVE

Rising intravenous drug use (IVDU) paralleled with an increasing dialysis-dependent end-stage renal disease population may pose a challenge for creating and maintaining arteriovenous (AV) access for hemodialysis. We aimed to elucidate baseline characteristics and outcomes of AV access creation in the IVDU population.

METHODS

The Vascular Quality Initiative (2011-2018) was queried for patients undergoing AV access placement. Univariable and multivariable analyses comparing outcomes of patients with and without IVDU history were performed.

RESULTS

Of 33,404 patients undergoing AV access creation, 601 (1.8%) had IVDU history (21.8% current and 78.2% past users). IVDU patients receiving AV access were more often younger, male, nonwhite, smokers, homeless, Medicaid recipients, and hospitalized at the time of surgery (P < .001 for all). They exhibited higher rates of congestive heart failure, chronic obstructive pulmonary disease, and human immunodeficiency virus/acquired immunodeficiency syndrome (P < .05 for all). They more frequently had tunneled catheters at the time of access creation (53.6% vs 42%; P < .001) and had a previous AV access (25.3% vs 21.7%; P = .002). IVDU patients more often received prosthetic AV grafts (28.6% vs 18%; P < .001) and more often had anastomoses created to basilic veins (33.1% vs 23.2%; P < .001) but less often to cephalic veins (36.8% vs 57.7%; P < .001). IVDU patients had longer postoperative length of stay (2 ± 6 days vs 0.9 ± 5 days; P < .001) but no significant difference in 30-day mortality (1.7% vs 1.2%; P = .3). Comparing IVDU vs no IVDU cohorts, 1-year access infection-free survival (85.4% vs 86.6%; P = .382), primary patency loss-free survival (39.5% vs 37.9%; P = .335), endovascular/open reintervention-free survival (58% vs 57%; P = .705), and overall survival (89.7% vs 88.9%; P = .635) were similar. On multivariable analysis, IVDU was independently associated with postoperative length of stay (odds ratio, 1.64; 95% confidence interval, 1.35-2; P < .001) but not with 30-day mortality or 1-year infection-free survival, primary patency loss-free survival, reintervention-free survival, and all-cause mortality. The null results were confirmed in a propensity score-matched cohort.

CONCLUSIONS

IVDU history was uncommon among patients undergoing AV access creation at Vascular Quality Initiative centers and was not independently associated with major morbidity or mortality postoperatively. IVDU patients more often received grafts or autogenous access with anastomoses to basilic veins. Although these patients frequently have more comorbidities, IVDU should not deter AV access creation.

Trends and Outcomes of Cardiovascular Surgery in Patients With Opioid Use Disorders

Importance

Persistent opioid use is currently a major health care crisis. There is a lack of knowledge regarding its prevalence and effect among patients undergoing cardiac surgery.

Objective

To characterize the national population of cardiac surgery patients with opioid use disorder (OUD) and compare outcomes with the cardiac surgery population without OUD.

Design, Setting, and Participants

In this retrospective population-based cohort study, more than 5.7 million adult patients who underwent cardiac surgery (ie, coronary artery bypass graft, valve surgery, or aortic surgery) in the United States were included. Pregnant patients were excluded. Propensity matching was performed to compare outcomes between cardiac surgery patients with OUD (n = 11 359) and without OUD (n = 5 707 193). The Nationwide Inpatient Sample database was queried from January 1998 to December 2013. Data were analyzed in January 2018.

Exposures

Persistent opioid use and/or dependence.

Main Outcomes and Measures

In-hospital mortality, complications, length of stay, costs, and discharge disposition.

Results

Among the 5 718 552 included patients, 3 887 097 (68.0%) were male; the mean (SD) age of patients with OUD was 47.67 (13.03) years and of patients without OUD was 65.53 (26.14) years. The prevalence of OUD among cardiac surgery patients was 0.2% (n = 11 359), with an 8-fold increase over 15 years (0.06% [262 of 437 641] in 1998 vs 0.54% [1425 of 263 930] in 2013; difference, 0.48%; 95% CI of difference, 0.45-0.51; P < .001). Compared with patients without OUD, patients with OUD were younger (mean [SD] age, 48 [0.30] years vs 66 [0.05] years; P < .001) and more often male (70.8% vs 68.0%; P < .001), black (13.7% vs 4.8%), or Hispanic (9.1% vs 4.8%). Patients with OUD more commonly fell in the first quartile of median income (30.7% vs 17.1%; P < .001) and were more likely to be uninsured or Medicaid beneficiaries (48.6% vs 7.7%; P < .001). Valve and aortic operations were more commonly performed among patients with OUD (49.8% vs 16.4%; P < .001). Among propensity-matched pairs, the mortality was similar between patients with vs without OUD (3.1% vs 4.0%; P = .12), but cardiac surgery patients with OUD had an overall higher incidence of major complications (67.6% vs 59.2%; P < .001). Specifically, the risks of blood transfusion (30.4% vs 25.9%; P = .002), pulmonary embolism (7.3% vs 3.8%; P < .001), mechanical ventilation (18.4% vs 15.7%; P = .02), and prolonged postoperative pain (2.0% vs 1.2%; P = .048) were significantly higher. Patients with OUD also had a significantly longer length of stay (median [SE], 11 [0.30] vs 10 [0.22] days; P < .001) and cost significantly more per patient (median [SE], $49 790 [1059] vs $45 216 [732]; P < .001).

Conclusions and Relevance

The population of patients with persistent opioid use or opioid dependency undergoing cardiac surgery has increased over the past decade. Cardiac surgery in patients with OUD is safe but is associated with higher complications and cost. Patients should not be denied surgery because of OUD status but should be carefully monitored postoperatively for complications.

Incidence and Cost of Acute Kidney Injury in Hospitalized Patients with Infective Endocarditis

Acute kidney injury (AKI) is a frequent complication of hospitalized patients with infective endocarditis (IE). Further, AKI in the setting of IE is associated with high morbidity and mortality. We aimed to examine the incidence, clinical parameters, and hospital costs associated with AKI in hospitalized patients with IE in an endemic area with an increasing prevalence of opioid use. This retrospective cohort study included 269 patients admitted to a major referral center in Kentucky with a primary diagnosis of IE from January 2013 to December 2015. Of these, 178 (66.2%) patients had AKI by Kidney Disease Improving Global Outcomes (KDIGO) serum creatinine criteria: 74 (41.6%) had AKI stage 1 and 104 (58.4%) had AKI stage ≥2. In multivariable analysis, higher comorbidity scores and the need for diuretics were independently associated with AKI, while the involvement of the tricuspid valve and the need for vasopressor/inotrope support were independently associated with severe AKI (stage ≥2). The median total direct cost of hospitalization was progressively higher according to each stage of AKI ($17,069 for no AKI; $37,111 for AKI stage 1; and $61,357 for AKI stage ≥2; p < 0.001). In conclusion, two-thirds of patients admitted to the hospital due to IE had incident AKI. The occurrence of AKI significantly increased healthcare costs. The higher level of comorbidity, the affection of the tricuspid valve, and the need for diuretics and/or vasoactive drugs were associated with severe AKI in this susceptible population.

Management of endocarditis among persons who inject drugs: A narrative review of surgical and psychiatric approaches and controversies

BACKGROUND

People who inject drugs (PWID) represent a high-risk subgroup of endocarditis patients. This is highlighted by poorer post-operative outcomes in injection drug use-related infective endocarditis (IDU-IE), which is largely attributable to the increased vulnerability of prosthetic valves to re-infection. Consequently, many centres do not perform valve replacement on these patients. A parallel, but often underrecognized, component of care is the role of multidisciplinary management for individuals with IDU-IE, including perioperative addictions and psychiatric care. Consequently, surgical management options in IDU-IE remain a controversial topic.

OBJECTIVES

To determine the characteristics of optimal surgical and psychiatric care for individuals with IDU-IE.

METHODS

We conducted a narrative synthesis of the findings of literature retrieved from searches of computerized databases, hand searches, and authoritative text, organizing the findings into several key themes: clinical characteristics and factors associated with mortality in IDU-IE, alternative surgical management options, perioperative risk stratification techniques, principles of psychiatric and addictions management in IDU-IE, ethical considerations and controversies, and future research directions.

RESULTS/CONCLUSIONS

Managing IDU-IE involves the treatment of two comorbidities: the intra-cardiac infection and the underlying substance use disorder. Cardiac surgery represents a high-intensity intervention with appreciable risk, and the benefit it is not always clear. As patients often present acutely, it is not feasible to use drug abstinence as a prerequisite to surgery. Involvement of inpatient psychiatry and addictions teams, however, appears to be an evidence-based approach that can bridge IDU-IE patients with opioid agonist therapy in hospital and adequate outpatient treatment options for their underlying addiction upon their discharge from hospital. It is likely that a majority of these patients are not receiving optimal psychiatric management despite increasing recognition of efficacy. Further interdisciplinary studies are needed to elucidate optimal surgical and multidisciplinary protocols.

BACKGROUND

Infective endocarditis (IE) is an infection of the innermost lining of the heart often affecting the heart valves. Over the last few decades, the epidemiology of IE has shifted in the developed world and while it continues to be a significant cause of morbidity and mortality, there has been a significant increased incidence among persons who inject drugs (PWID). To date, well-conducted epidemiologic studies of IE among PWID have been sparse, which has limited our ability to fully characterize this disease phenomenon. To address this knowledge deficit, we conducted a narrative synthesis of the findings of literature retrieved from searches of computerized databases, hand searches, and authoritative text, and organized our findings into six key themes: clinical characteristics and factors associated with mortality in IDU-IE, alternative surgical management options, perioperative risk stratification techniques, principles of psychiatric and addictions management in IDU-IE, ethical considerations and controversies, and future research directions.