Statin use associated with lower mortality in very elderly patients with peripheral arterial disease

Introduction

Given the potential side effects and the lack of data on its efficacy, the role of statins in the very elderly (age 75+) with peripheral arterial disease (PAD) is uncertain. Previous studies have shown significant mortality benefit in very elderly patients with coronary artery disease, but the effect in PAD has not been evaluated.

Methods

Very elderly patients aged 75 to 80 with at least five years of follow-up who underwent ankle-brachial index (ABI) measurement were included. PAD was defined as either low ABI <0.90 or high ABI >1.40. Demographic, medication use, comorbidity and mortality data was obtained using the electronic medical record. Univariate and multivariate Cox proportional hazard analyses were performed.

Results

In total, 4,560 very elderly subjects with PAD were included in the analysis. The median age was 77 (interquartile range 76–79) and 39% were female. 3,462 (76%) had low ABI while 1098 (24%) had high ABI. Univariate analysis showed that patients on statins were more likely to be male, have diabetes, have coronary artery disease, and have hyperlipidemia. Overall, 1,355 (30%) patients died in the five-year period. Unadjusted all-cause mortality hazard ratios for patients with low or high ABI with statin use was 0.66 (95% confidence interval [CI]: 0.57–0.75) and 0.80 (95% CI: 0.66–0.97), respectively. After adjusting for age, sex, coronary artery disease and diabetes, statin use in low and high ABI was still associated with significant reductions in risk of all-cause mortality of 0.59 (95% CI: 0.51–0.67) and 0.66 (95% CI: 0.54–0.80), respectively. The survival curve for very elderly patients with PAD by statin use is shown in Figure 1.

Conclusion

Statin use in the very elderly was associated with lower risk of all-cause mortality in the five-year period after diagnosis of PAD. There appears to be a mortality benefit with statin use in the very elderly with PAD, though careful consideration of benefits and side effects should be individualized in this age group.

Figure 1

Funding Acknowledgement

Type of funding source: None

Complex antithrombotic therapy and bleeding risk in patients with peripheral arterial disease

Introduction

Antiplatelet therapy is the cornerstone of treatment for many atherosclerotic vascular pathologies including peripheral arterial disease (PAD). Patients with PAD often have comorbid conditions that require complex antithrombotic therapy, i.e. combined antiplatelet and anticoagulation.

Methods

All adult patients undergoing ankle brachial index (ABI) measurements were included in the study. ABI values between 1.00 and 1.40 were considered normal, and values below 1.00 or above 1.40 were considered PAD. Demographic, comorbidity and outcome data were obtained using diagnostic codes from the electronic health record. Three medication classes were analyzed: aspirin, non-aspirin oral antiplatelets (e.g. P2Y12 inhibitors) and oral anticoagulants (warfarin and the direct oral anticoagulants). Medication use was determined for patients who had been on a medication for at least one year. Cox proportional hazard analysis for the time to first bleeding event was analyzed. Bleeding was defined as any bleeding requiring medical evaluation (including clinically-relevant non-major bleeding and major bleeding).

Results

In all, 40,144 patients were included in the analysis (mean age 66±15, 43% female). Patients with PAD were more likely to be on double therapy (one antiplatelet with anticoagulation) (28% vs 19%) and triple therapy (dual antiplatelet with anticoagulation) (10% vs 4%). Unadjusted hazard ratios for bleeding risk showed increased risk of bleeding for patients with PAD (1.18, 95% confidence interval [CI]: 1.08–1.29), though the association is no longer present after adjustment for antithrombotic therapy. Adjusting for age, sex and PAD class, compared to no antithrombotic therapy, there was increased risk of bleeding for monotherapy (1.91, 95% CI: 1.61–2.26), double therapy (3.40, 95% CI: 2.89–4.00) and triple therapy (5.00, 95% CI: 4.21–5.96). Among medications, aspirin and anticoagulant use was independently associated with the greatest increase in risk of bleeding.

Conclusion

Patients in PAD are at increased risk of bleeding secondary to antithrombotic therapy. Complex antithrombotic therapy with double or triple therapy confer additional bleeding risk, particularly regimens containing aspirin and oral anticoagulants.

Funding Acknowledgement

Type of funding source: None

P946Abnormal ankle brachial indices are associated with ischemic stroke: evidence from a large cohort study

Background

Peripheral arterial disease is a marker of aggressive atherosclerosis. The ankle brachial index (ABI) is a simple and non-invasive tool to diagnose peripheral arterial disease (PAD). Patients with PAD are at increased risk for ischemic strokes and other cardiovascular diseases.

Purpose

To evaluate the association of abnormal ABI and poorly compressible vessels with ischemic stroke in a large patient cohort.

Methods

We analyzed lower extremity vascular studies of all patients with ABI measurements at a tertiary care hospital between January 1996 and August 2018. PAD is defined as ABI<1.0, and poorly or non-compressible (PC/NC) arteries as ABI>1.4 while ABI between 1.0–1.4 is normal. Association of these ABIs with new ischemic stroke events post ABI measurement were analyzed after adjusting for high risk confounders such as atrial fibrillation. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals.

Results

In total, 38,016 unique patients (mean age 66.1±14.8 years, female 42.3%) were included. Abnormal ABI was found to be more prevalent among elderly male patients compared to patients with normal ABI. In contrast to non-PAD patients, both PAD and PC/NC patients as defined by ABI had a statistically significant risk of ischemic stroke, with PAD conferring the greatest risk compared to PC/NC vessels. The data is summarized in Table 1.

Table 1 Unadjusted HR p-value Adjusted HR p-value PAD vs. No PAD 2.77 (2.62, 2.92) <0.001 2.10 (1.98, 2.22) <0.001 PC/NC vs. No PAD 2.11 (1.95, 2.28) <0.001 1.38 (1.26, 1.51) <0.001 PAD vs. PC/NC 1.37 (1.28, 1.46) <0.001 1.37 (1.28, 1.48) <0.001 Adjusted and unadjusted hazard ratios with p-values. HR adjusted for age, sex, atrial fibrillation, ischemic stroke, transient ischemic attack, chronic heart failure, diabetes mellitus, hyperlipidemia, hypertension, and coronary artery disease. PAD = Peripheral artery disease and PC/NC = poorly compressible/non-compressible.

Conclusion

This study adds to the growing body of evidence that PAD and poorly-compressible vessels are independently associated with an increased risk of ischemic stroke. Given the associated risk of cerebrovascular disease, clinicians should aggressively treat to minimize risk factors in those with abnormal ABIs.

P945Abnormalities in ankle-brachial indices are independently associated with new-onset atrial fibrillation

Introduction

Lower extremity physiologic studies are an important non-invasive diagnostic tool in peripheral arterial disease (PAD). PAD and atrial fibrillation (AF) are associated with increased cardiovascular and all-cause mortality.

Purpose

To evaluate the association between PAD and new-onset AF and the risk of stroke.

Methods

We performed a study of all patients without AF undergoing ankle-brachial index (ABI) for any indication between January 1996 to June 2018. The ABI cut-off were as follows: abnormal ABI (0–0.99), normal ABI (1.00–1.39) and poor vessel compressibility (PC) (1.40+). Demographic, comorbidity, and outcome variables were extracted using the electronic medical record.

Results

Overall, 34,441 patients (mean age 66.8±14.3, 57.3% male, 88.2% white) were included in the study with a median follow-up of 7.2 years (interquartile range, 3.0–12.9 years). Multivariate Cox proportional hazard analysis showed increased risk of new-onset AF for male sex, older age, hypertension, coronary artery disease, cerebrovascular disease, chronic kidney disease stage III or greater, congestive heart failure, chronic obstructive pulmonary disease, and cancer (all p<0.0001). After adjustment, ABI results were significantly associated with new-onset AF, particularly poorly-compressible vessels (adjusted HR: 1.42 (1.30–1.55), p<0.0001) compared to abnormal ABI (adjusted HR: 1.12 (1.05–1.20), p=0.0012). Patients with atrial fibrillation were more likely to experience ischemic stroke (39.2% versus 16.1%, p<0.0001).

Conclusion

Abnormalities in ABI results, particularly poorly-compressible vessels, are independently associated with new-onset atrial fibrillation in a large ambulatory cohort. While the mechanism cannot be assessed, common inflammatory mechanisms and increased vascular stiffness may play an important role. Identification of AF in these at-risk patients may improve cardiovascular outcomes.

The role of melatonin in the pathogenesis of adolescent idiopathic scoliosis (AIS)

The cause of adolescent idiopathic scoliosis (AIS) in humans remains obscure and probably multifactorial. At present, there is no proven method or test available to identify children or adolescent at risk of developing AIS or identify which of the affected individuals are at risk of progression. Reported associations are linked in pathogenesis rather than etiologic factors. Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis), but at present, the data available cannot clearly show the role of melatonin in producing scoliosis in humans. The data regarding human melatonin levels are mixed at best, and the melatonin deficiency as a causative factor in the etiology of scoliosis cannot be supported. It will be an important issue of future research to investigate the role of melatonin in human biology, the clinical efficacy, and safety of melatonin under different pathological situations. Research is needed to better define the role of all factors in AIS development.

Uninstrumented posterolateral spinal arthrodesis: is it the gold standard technique for I degrees and II degrees grade spondylolisthesis in adolescence?

We retrospectively reviewed the outcome of uninstrumented posterolateral spinal arthrodesis in 49 patients with lumbar isthmic spondylolisthesis grades I degrees and II degrees in adolescent patients in the time of surgery, who participate at follow-up, between 1980 and 1995. The goal of our study is to analyse the clinical and radiographic imaging at long follow-up in uninstrumented posterolateral arthrodesis and to evaluate the efficiency and the validity of surgical technique in young patients (<18 years). All patients had failed previous conservative treatment. The average age at follow-up was 33.5 years (range 25-42 years) and the average follow-up time was 19.7 years (range 12-27 years). The clinical outcome measures were the Oswestry Disability Index, the SF-36, and the visual analogic score. All measures assessed the endpoint outcomes at 20 years after surgery. The outcome of spinal fusion was good with 43 (87.7%) patients attaining solid fusion, pseudoarthrosis in 6 patients (12.3%). None of our patients complained of excessive postoperative wound pain. Additionally, no complications, such as wound infection, were encountered. Satisfactory results were obtained in 94% of patients and this was closely associated with the rate of successful fusion. The results suggest that clinical outcome is closely related to the attainment of solid fusion.

Evaluation of conservative treatment of non specific spondylodiscitis

The objective of this study was to analyse the presentation, aetiology, conservative management, and outcome of non-tuberculous pyogenic spinal infection in adults. We performed a retrospective review of 56 patients (35 women and 21 men) of pyogenic spinal infection presenting over a 7-year period (1999-2006) to the Department of Spinal Surgery of Hesperia Hospital. The medical records, radiologic imaging, bacteriology results, treatment, and complications of all patients were reviewed. The mean age at presentation was 47.8 years (age range 35-72 years), the mean follow-up duration was 12.5 months. The most common site of infection was lumbar spine (n: 48), followed by the thoracic spine (n: 8). Most patients were symptomatic for between 4 and 10 weeks before presenting to hospital. The frequently isolated pathogen was Staphylococcus aureus in 31 of 56 cases (57.6%). Percutaneous biopsies were diagnostic in 57% of patients; the open biopsy was indicated if closed biopsy failed and when the infection was not accessible by percutaneous technique. The patients were managed by conservative measures alone, including antibiotic therapy and spinal bracing. The mean period of antibiotic therapy was 8.5 weeks (range 6-9 weeks), followed by oral antibiotics for 6 weeks. All patients had a supportive spinal brace for mean 8 weeks (range 6-10 weeks). The duration of the administration of oral antibiotics was dependent on clinical and laboratory evidence (white cell count, erythrocyte sedimentation rate, C-reactive protein) that the infection was resolved. The follow-up MR gadolinium scans were essential to monitor the response to medical treatment. The diagnosis of pyogenic spinal infection should be considered in any patient presenting with severe localised unremitting back and neck pain, especially when accompanied with systemic features, such as fever and weight loss and in the presence of elevated inflammatory markers. The conservative management of infection with antibiotic therapy and spinal bracing was very successful.

Late post-operative paraparesis after rib penetration of the spinal canal in a patient with neurofibromatous scoliosis

Rib displacement into the spinal canal is a rare cause of paraplegia or paraparesis in patients affected by neurofibromatous scoliosis. We describe a case of paraparesis in a 14-year-old child affected by neurofibromatous dystrophic kyphoscoliosis, treated with combined posterior and anterior spinal arthrodesis. Seventeen days after the surgical treatment the patient developed clinical signs and symptoms of paraparesis. A CT scan showed the head of the fifth rib protruding into the spinal canal with cord compression. Rib resection and posterior cord decompression were carried out following complete neurological recovery.