Diagnosis of Pulmonary Embolism: A Review of Evidence-Based Approaches.

Venous thromboembolism, commonly presented as pulmonary embolism and deep-vein thrombosis, is a paramount and potentially fatal condition with variable clinical presentation. Diagnosis is key to providing appropriate treatment in a safe and timely fashion. Clinical judgment and assessment using clinical scoring systems should guide diagnostic testing, including laboratory and imaging modalities, for optimal results and to avoid unnecessary testing.

High ankle-brachial index participants experienced similar long-term mortality as peripheral artery disease in a national sample of community-dwelling adults.

BACKGROUND: Only a few small studies have shown the association between high ankle-brachial pressure index (ABI >1.4) and adverse cardiovascular (CV) events and mortality. Although there is abundant literature depicting the association between ABI and overall systemic atherosclerosis, it typically focuses on low ABI. Furthermore, historically, many studies focusing on peripheral artery disease have excluded high ABI participants. We aimed to study the mortality outcomes of persons with high ABI in the National Health and Nutrition Examination Survey (NHANES). METHODS: We obtained ABI from participants aged ≥40 years for survey years 1999 to 2004. We defined low a ABI as ≤0.9, normal ABI as 0.9 to 1.4, and high ABI as >1.4 or if the ankle pressures were >245 mm Hg. Demographics, various comorbidities, and laboratory test results were obtained at the time of the survey interview. Multivariable adjusted hazard ratios (HRs) along with 95% confidence intervals (CIs) were calculated for CV and all-cause mortality via Cox proportional hazards regression. Mortality was linked to all NHANES participants for follow-up through December 31, 2019, by the Centers for Disease Control and Prevention. RESULTS: We identified 7639 NHANES participants with available ABI. Of these, 6787 (89%) had a normal ABI, 646 (8%) had a low ABI, and 206 (3%) had elevated ABI. Of participants with high ABI, 50% were men, 15% were African Americans, 10% were current smokers, 56% had hypertension, 33% had diabetes, 15% had chronic kidney disease (CKD), and 18% had concomitant coronary artery disease (CAD). Diabetes (odds ratio [OR], 2.4; 95% CI, 1.7-3.2), CAD (OR, 1.6; 95% CI, 1.0-2.4), and CKD (OR, 1.5; 95% CI, 1.0-2.3) at baseline were associated with having a high ABI, respectively. A high ABI was associated independently with elevated CV (HR, 2.6; 95% CI, 2.1-3.1; P < .0001) and all-cause mortality (HR, 2.5; 95% CI, 2.2-2.8; P < .0001) after adjusting for covariates, including diabetes, CKD, CAD, current smoking, cancer, and hypertension. CONCLUSIONS: A high ABI is associated with an elevated CV and all-cause mortality, similar to patients with PAD. High ABI participants should receive the same attention and aggressive medical therapies as patients with PAD.

Outcomes of peripheral artery disease and polyvascular disease in patients with end-stage kidney disease.

OBJECTIVE: Patients with peripheral artery disease (PAD) and end-stage kidney disease are a high-risk population, and concomitant atherosclerosis in coronary arteries (CAD) or cerebral arteries (CVD) is common. The aim of the study was to assess long-term outcomes of PAD and the impact of coexistent CAD and CVD on outcomes. METHODS: The United States Renal Data System was used to identify patients with PAD within 6 months of incident dialysis. Four groups were formed: PAD alone, PAD with CAD, PAD with CVD, and PAD with CAD and CVD. PAD-specific outcomes (chronic limb-threatening ischemia, major amputation, percutaneous/surgical revascularization, and their composite, defined as major adverse limb events [MALE]) as well as all-cause mortality, myocardial infarction, and stroke were studied. RESULTS: The study included 106,567 patients (mean age, 71.2 years; 40.8% female) with a median follow-up of 546 days (interquartile range, 214-1096 days). Most patients had PAD and CAD (49.8%), 25.8% had PAD alone, and 19.2% had all three territories involved. MALE rate in patients with PAD was 22.3% and 35.0% at 1 and 3 years, respectively. In comparison to PAD alone, the coexistence of both CAD and CVD (ie, polyvascular disease) was associated with a higher adjusted rates of all-cause mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.24-1.31), myocardial infarction (HR, 1.78; 95% CI, 1.69-1.88), stroke (HR, 1.66; 95% CI, 1.52,1.80), and MALE (HR, 1.07; 95% CI, 1.04-1.11). CONCLUSIONS: Patients with end-stage kidney disease have a high burden of PAD with poor long-term outcomes, which worsen, in an incremental fashion, with the involvement of each additional diseased arterial bed.

Statin use improves limb salvage after intervention for peripheral arterial disease.

BACKGROUND: Statin use is recommended in all patients with peripheral arterial disease (PAD) owing to its morbidity and mortality benefits. However, the effect of statin use on limb salvage in patients with PAD after intervention is unclear. We examined the effect of statin use on limb salvage and survival among patients with PAD undergoing surgical or endovascular intervention. METHODS: A total of 488 patients with PAD were identified who underwent surgical (n = 297) or endovascular (n = 191) intervention between 2009 and 2010. Information was collected from electronic medical records and the Social Security Death Index. Predictors of ongoing statin use were identified first by univariate analysis and then via multivariable logistic regression. Survival and freedom from amputation were identified using Kaplan-Meier plots and adjusted hazard ratios by Cox regression. RESULTS: Of the 488 patients with PAD with intervention, 39% were non-whites, 44% were females, 41% received statins, 56% received antiplatelets, 26% received oral anticoagulants, 9% required a major amputation, and 11% died during follow-up of up to 88 months. Statin users were more often male (P = .03), white (P = .03), smokers (P < .01), and had higher comorbidities such as coronary artery disease (P < .01), hypertension (P < .01), and diabetes (P < .01). Antiplatelet use was not associated with limb salvage (P = .13), but did improve survival (P < .01). Dual antiplatelet therapy did not show any benefit over monotherapy for limb salvage (P = .4) or survival (P = .3). Statin use was associated with improved survival (P = .04), and improved limb salvage (hazard ratio, 0.3; 95% confidence interval, 0.1-0.7) after adjusting for severity of disease, traditional risk factors, and concurrent antiplatelet use. CONCLUSIONS: Statin use in patients with PAD with interventions was associated with improved limb salvage and survival. Despite existing guidelines, statin therapy was low in our PAD population, and efforts are ongoing to increase their use across the health care system.

Influence of Age on Warfarin Dose, Anticoagulation Control, and Risk of Hemorrhage.

OBJECTIVE: We assessed the influence of age on warfarin dose, percentage time in target range (PTTR), and risk of major hemorrhage. DESIGN: Warfarin users recruited into a large prospective inception cohort study were categorized into three age groups: young (younger than 50 yrs), middle aged (50-70 yrs), and elderly (older than 70 yrs). The influence of age on warfarin dose and PTTR was assessed using regression analysis; risk of major hemorrhage was assessed using proportional hazards analysis. Models were adjusted for demographic, clinical, and genetic factors. SETTING: Two outpatient anticoagulation clinics. PARTICIPANTS: A total of 1498 anticoagulated patients. OUTCOMES: Warfarin dose (mg/day), PTTR, major hemorrhage. RESULTS: Of the 1498 patients, 22.8% were young, 44.1% were middle aged, and 33.1% were elderly. After accounting for clinical and genetic factors, compared with young warfarin users, warfarin dose requirements were 10.6% lower among the middle aged and an additional 10.6% lower for the elderly. Compared with young patients, middle-aged and elderly patients spent more time in target international normalized ratio (INR) range (p<0.0001), despite having fewer INR assessments (p<0.0001). Compared with young warfarin users, absolute risk of hemorrhage was marginally higher among the middle aged (p=0.08) and significantly higher among the elderly (p=0.016). Compared with young warfarin users, after adjustment, the relative risk of hemorrhage increased by 31% for each age category (p=0.026). CONCLUSIONS: In a real-world setting, despite achieving better anticoagulation control, elderly patients had a higher risk of major hemorrhagic events. As the population ages and the candidacy for oral anticoagulation increases, strategies that mitigate the elevated risk of hemorrhage need to be identified.

Effect of lipid-modifying drug therapy on survival after abdominal aortic aneurysm repair.

BACKGROUND: Lipid-modifying drug therapy (LMDT) is recommended in all patients having coronary or noncoronary atherosclerotic disease. However, the effect of LMDT after abdominal aortic aneurysm (AAA) repair, especially in the absence of other atherosclerotic manifestations, is unclear. We examined the distribution of prevalence of LMDT among patients undergoing AAA repair and its effect on survival in the presence and absence of other atherosclerotic diseases. METHODS: We identified patients treated at University of Alabama at Birmingham between 1985 and 2010 who had a prior AAA repair. Information was collected from health system medical charts, medical communication, and national death indices. We assessed the predictors of prevalence of LMDT by univariate analysis using t-test for continuous and χ(2) test for categorical variables, and then performed multivariate logistic regression. The survival was determined using Kaplan-Meier plots, and adjusted hazard ratios were calculated using Cox proportion regression. RESULTS: A total of 2063 patients underwent AAA repair procedure. Of these, 9% were African-American, and 20% were female. Thirty-five percent received LMDT, and 32% died during the follow-up period of up to 240 months. Significant predictors for being on LMDT included white race (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2), presence of other atherosclerotic disease or diabetes (OR, 2.4; 95% CI, 1.9-3.0), hypertension (OR, 4.0; 95% CI, 3.1-5.2), smoking (OR, 1.6; 95% CI, 1.2-2.1), and endovascular AAA repair (OR, 1.9; 95% CI, 1.5-2.3). LMDT was associated with improved survival (hazard ratio, 0.6; 95% CI, 0.5-0.8) after controlling for traditional risk factors, diabetes, and other atherosclerotic diseases. CONCLUSIONS: LMDT after AAA is associated with an increased survival compared with patients who were not using drug therapy for dyslipidemia. Aggressive management of dyslipidemia should be considered in all patients undergoing AAA repair irrespective of other atherosclerotic disease status and risk factor profile.

Protocol implementation of selective postoperative lumbar spinal drainage after thoracic aortic endograft.

BACKGROUND: Spinal cord ischemia (SCI) remains a significant concern in patients undergoing endovascular repair involving the thoracic aorta (thoracic endovascular aortic repair [TEVAR]). Perioperative lumbar spinal drainage has been widely practiced for open repair, but there is no consensus treatment protocol using lumbar drainage for SCI associated with TEVAR. This study analyzes the efficacy of an institutional protocol using selective lumbar drainage reserved for patients experiencing SCI following TEVAR. METHODS: A prospectively maintained registry was reviewed to identify all patients who underwent TEVAR from January 2000 through June 2010. Preoperative characteristics, intraoperative details, and outcomes, including neurologic deficit and mortality at 30 days and 1 year were determined based on reporting standards. Patients developing symptoms of SCI in the postoperative setting were compared with those without neurologic symptoms. SCI patients who received selective lumbar drainage were grouped based on resolution of neurologic function, with risk factors and outcomes of these subgroups analyzed with χ(2), t test, logistic regression, and analysis of variance (ANOVA). RESULTS: Two hundred seventy-eight TEVARs were performed on 251 patients. Twelve patients accounting for 12 TEVARs were excluded from analysis: 5 patients experienced SCI preoperatively, 4 patients were drained preoperatively, 2 expired intraoperatively, and 1 procedure was aborted. Of the remaining 266 procedures in 239 patients, 16 (6.0%) developed SCI within the 30-day postoperative period. Risk factors for SCI reaching statistical significance included length of aortic coverage (P = .036), existence of infrarenal aortic pathology (P = .026), and history of stroke (P = .043). Stent graft coverage of the left subclavian artery origin was required in 28.9% (n = 77) and was not associated with SCI (P = .52). Ten of 16 post-TEVAR SCI patients received selective postoperative lumbar drains and were categorized based on resolution of symptoms into complete resolution (n = 3; 30%), partial resolution (n = 4; 40%), and no resolution (n = 3; 30%). No patient characteristics or risk factors reached significance in comparison of lumbar drained patients and nondrained patients. All seven drained patients without complete resolution of SCI died within the first year after surgery, while all three of the complete responders survived (P = .017). In patients with SCI, increased all-cause mortality was observed at 1 year (56.3% vs 20.4%; P = .003). CONCLUSIONS: A protocol utilizing selective postoperative lumbar spinal drainage can be used safely for patients developing SCI after TEVAR with acceptably low permanent neurologic deficit, although overall survival of patients experiencing SCI after TEVAR is diminished relative to non-SCI patients.

Long-term single institution comparison of endovascular aneurysm repair and open aortic aneurysm repair.

INTRODUCTION: Since the development of endovascular aneurysm repair (EVAR), there remains concerns regarding its durability, need for secondary procedures, and associated long-term morbidity. We compared these two approaches to evaluate secondary interventions and their respective long-term durability. METHODS: All patients who had undergone endovascular and open abdominal aortic aneurysm (AAA) repair were identified from a prospectively maintained registry. Health system charts, medical communication, and national death indexes were reviewed. Secondary interventions were classified as vascular (aortic graft or remote) and nonvascular (incisional or gastrointestinal). RESULTS: Between July 1985 and September 2009, 1908 patients underwent 1986 AAA repair procedures (EVAR = 1066; open = 920). Patients were followed up to 290 months (mean 27.6 ± 35.9) and identified with 427 surgical encounters (EVAR 233% to 21.9%; open 194% to 21.1%). Most encounters (338% to 74.6%) were related to vascular disease: 178 (EVAR = 131; open = 47) related to the aortic graft; 160 (EVAR = 93; open = 67) were related to nonaortic vascular disease. The remaining 89 surgical encounters included incisional hernias, small bowel obstruction, intra-abdominal abscesses, and wound dehiscence requiring operation. Of these 89 encounters (EVAR = 9; open = 80), 44 patients required surgical intervention and 36 required hospitalization without surgical procedure. Over the period of 100 months, the all-cause mortality rate was 25.2% after EVAR and 39.1% after open repair. One-year survival was 88.0% (SE 0.01) and 85.0% (SE 0.01), while 5-year survival was 58.0% (SE 0.02) and 53.0% (SE 0.02) for EVAR and open repair, respectively (log-rank P value < .0164). Seven-year survival was 46% (SE 0.03) for EVAR and 36% (SE 0.03) for open AAA repair. CONCLUSION: EVAR requires more late secondary vascular interventions than open AAA repair, but patients who undergo open repair have more nonvascular long-term morbidity. Long-term survival is better after EVAR compared to open repair in this selected patient group.