Analysis of endovascular therapy for peripheral arterial disease in all German hospitals

Background: The quality of vascular care has significantly improved in part by the expansion of endovascular techniques for the treatment of symptomatic peripheral artery disease (PAD) in recent years. In Germany these are primarily provided by the three disciplines of vascular surgery, angiology, and interventional radiology (IR). However, the relative contribute of angiologists to the total number of cases performed is unknown. Patients and methods: In the present study, we analysed the respective contribution of vascular surgery, angiology, and IR to the delivery of endovascular revascularisations in symptomatic PAD in Germany based on the legally mandatory quality reports representative for the reporting year 2018. Results: Vascular surgery is the most common speciality reporting procedures in German hospitals (n=579; 25.1%), followed by IR (n=264; 11.5%), angiology (n=189; 8.2%) and cardiology (n=17; 0.7%). The combination of vascular surgery and IR was reported in 202 (8.8%), vascular surgery and angiology in 167 (7.2%) and angiology and IR in 65 (2.8%) hospitals, and 63 (2.7%) hospitals reported the combination of all three disciplines. Not every department performed catheter interventions. The analysis of procedures per centre revealed that angiology centres provided the highest numbers for both basic procedures and more complex techniques such as atherectomy, rotational thrombectomy, lithoplasty, selective thrombolysis or the use of re-entry devices. In total, angiology centres provided 24.4% of the total procedures or 23.9% of the so-called basic procedures as a surrogate for patient numbers. Conclusions: While each of the disciplines contribute significantly to the endovascular procedures, angiology centres perform more procedures per centre and more complex procedures than the other disciplines highlighting the important quantitative and qualitative contribution of angiology specialists to the care of vascular patients. The inpatient catheter interventional care of patients with PAD is still too rarely carried out in a multi-disciplinary manner in Germany.

Secondary Prevention in Lower Extremity Artery Disease Patients: Lipid-Lowering Therapy and Long-Term Guideline Adherence

Lower extremity artery disease (LEAD) affects millions of elderly patients and is associated with elevated cardiovascular morbidity and mortality. Risk factor modification, including the therapy of dyslipidaemia, is mandatory to reduce cardiovascular event rates and to improve survival rates. However, only a minority achieve the recommended low-density lipoprotein cholesterol (LDL-C) target level < 55 mg/dL, according to the current ESC/EAS guidelines on the treatment of dyslipidaemia. This study elucidated the implementation of the lipid-lowering guideline recommendations of 400 LEAD patients with LDL-C > 100 mg/dL and their adherence to treatment adjustment during follow-up. Despite a sustained statin prescription in 93% of the patients, including 77% with high-intensity statins at follow-up, only 18% achieved the target level. Ezetimibe appeared in 21% and LDL-C goals were reached significantly more often with combination therapy. Recurrent revascularization appeared more often (28%) than coronary artery or cerebrovascular disease progression (14%) and 7% died. Despite the frequent use of high-intensity statins and expandable rates of ezetimibe, the progression of cardiovascular events remained inevitable. Only 18% of the patients had received recommendations on lifestyle modification, including dietary adaptations, which is key for a holistic approach to risk factor control. Thus, efforts for both pharmacological and behavioral strategies are needed to improve clinical outcomes and survival rates.

Clinical Characteristics and Current Practice of Endovascular Revascularization in Aorto-Iliac, Femoropopliteal and Infra-Popliteal Lower Extremity Artery Disease-Insights from the RECCORD Registry

BACKGROUND

Endovascular revascularization (EVR) is a pillar of therapeutic management in patients with symptomatic lower extremity artery disease (LEAD). Due to lack of scientific evidence, the approach of EVR type and the devices used at the different anatomic vascular segments of the lower limbs vary substantially between operators and centers. We analyzed data from the RECcording COurses of vasculaR Diseases (RECCORD) registry to assess the current real-world EVR treatment patterns in relation to anatomic vascular segments in symptomatic LEAD patients in Germany.

PATIENTS AND METHODS

RECCORD is an ongoing, prospective, multicenter, all-comers and entirely web-based registry platform. Baseline demographic and periprocedural data of patients undergoing EVR for symptomatic LEAD were assessed and performed EVRs were grouped according to the intervened anatomic vascular segment. We analyzed four EVR groups comprising either the aorto-iliac, femoropopliteal, or infrapopliteal segments (all these EVRs with or without a further intervention in another anatomic segment) or the infrapopliteal segment alone.

RESULTS

A total of 2210 EVR segments (in 1639 patients) were analyzed. Of those 616 (27.9%) were aorto-iliacal, 1346 (60.9%) femoropopliteal, 248 (11.2%) infrapopliteal and 104 (4.7%) only infrapopliteal segments. Aorto-iliac EVR was associated with younger age, smoking, claudication and simple lesions, while the distal infrapopliteal EVRs were related to advanced age, diabetes, multiple comorbidities, limb threatening ischemia and complex lesions. The use of different EVR devices at the aorto-iliac, femoropopliteal, infrapopliteal and only infrapopliteal segments were: only ballon-angioplasty: 8.3%, 12.9%, 58.1% and 63.5%; stenting: 82.3%, 45.3%, 16.9% and 12.5%; drug-coated balloon: 11.2%, 55.0%, 19.4% and 19.2%.

CONCLUSION

The RECCORD registry data demonstrate that in LEAD clinical and lesion characteristics are related to anatomic vascular segments. Despite the clear relationship between vascular segments and the current use of device types, prospective, segment-specific clinical studies are warranted to establish a consistent, evidence-based path for EVR in LEAD.

Outcome in octogenarian patients with lower extremity artery disease after endovascular revascularisation: a retrospective single-centre cohort study using in-patient data

OBJECTIVES

To investigate the clinical benefit of endovascular revascularisation (EVR) in octogenarian (aged ≥80 years) patients with lower extremity artery disease (LEAD).

DESIGN

Retrospective single-centre study.

SETTING

University hospital with a specialised centre for vascular medicine.

PARTICIPANTS

681 LEAD patients undergoing EVR between 2010 and 2016 were stratified by age.

MAIN OUTCOME MEASURE

Technical success, complications and mortality.

RESULTS

The cohort comprised 172 (25.3%) octogenarian and 509 (74.7%) non-octogenarian patients. Despite higher LEAD stages and complexity of EVR in octogenarians, primary technical success rate (79% octogenarians vs 86% non-octogenarians, p=0.006) and 1-year survival (87% vs 96%, p<0.001) were overall on high levels. Especially for the octogenarians, 1-year survival depends on the presence of chronic limb-threatening ischaemia (CLTI) (octogenarians: non-CLTI 98%; CLTI 79% p<0.001 vs non-octogenarians: non-CLTI 99%; CLTI 91%, p<0.001). In octogenarians, female sex (HR 0.45; 95% CI (0.24 to 0.86); p=0.015), the intake of statins (HR 0.34; 95% CI 0.19 to 0.65; p=0.001) and platelet aggregation inhibitors (HR 0.10; 95% CI 0.02 to 0.45; p=0.003) were independently associated with improved survival after EVR.

CONCLUSION

EVR can be performed safely and with sustained clinical benefit also in octogenarian patients with LEAD. After-care including medical adherence is of particular importance to improve long-term survival.

Mortality after use of paclitaxel-based devices in peripheral arteries: a real-world safety analysis

AIMS

Drug-eluting devices (DED) represent a well-established therapy being widely used for endovascular revascularization (EVR) of peripheral vessels. Recent data indicate a two-fold increased long-term mortality in patients treated with paclitaxel-based DED. The subsequent safety concerns affected international regulatory authorities to enunciate several alerts for further application of DED.

METHODS AND RESULTS

In 9.2 million insurants of the German BARMER Health Insurance, data on the application of paclitaxel-based drug-eluting stents (DES) and drug-coated balloons (DCB) were retrieved from their introduction on the market in 2007 until present. All patients with first EVR between 2007 and 2015 were indexed and followed until 31 December 2017. Each subsequently applied DES, DCB, bare-metal stent, and uncoated balloon was included in further analyses. Multivariable Cox regression analysis considered potential non-linear time-dependent hazard ratios (HRs) of DES and DCB over 11 years. We identified 64 771 patients who underwent 107 112 EVR procedures using 23 137 DED. Multivariable Cox regression analysis showed paclitaxel-based DES not to be associated with increased long-term mortality for over 11 years past application (all P > 0.057). DCB was associated with decreased long-term mortality for the first year past application (HR 0.92; P < 0.001), and indifferent correlation in the years thereafter (all P > 0.202).

CONCLUSION

Our real-world analysis showed no evidence for increased mortality associated with paclitaxel-based DED for over 11 years.

Feasibility and impact of carbon dioxide angiography on acute kidney injury following endovascular interventions in patients with peripheral artery disease and renal impairment

BACKGROUND

Post-contrast acute kidney injury (AKI) is a dreaded complication of endovascular revascularization using iodinated contrast medium in patients with peripheral artery disease and concomitant chronic kidney disease (CKD). This study sought to evaluate the incidence of AKI in patients with peripheral artery disease and CKD undergoing endovascular revascularization and using carbon dioxide (CO₂) as contrast medium.

METHODS AND RESULTS

From 04/2015 to 07/2018, all consecutive peripheral artery disease patients with CKD stage ≥ 3 referred for endovascular revascularization of symptomatic peripheral artery disease were prospectively included. During endovascular revascularization, CO₂ as contrast medium was manually injected and iodinated contrast medium was additionally used when needed. The reference group consisted of 211 cardiovascular risk factor-matched patients undergoing endovascular revascularization with iodinated contrast medium only. CO₂-guided endovascular revascularization was performed in 102 patients, thereof 16 (15.7%) patients exclusively with CO₂. Baseline CKD stage ≥ 4 and iodinated contrast medium volume > 50 ml were disproportionally associated with post-procedural post-contrast AKI. At CKD stage 4 the odds ratio for post-contrast AKI was 13.2 (95% CI 1.489-117.004; p = 0.02) for iodinated contrast medium volume 51-100 ml and 37.7 (95% CI 3.927-362.234; p = 0.002) for iodinated contrast medium volume > 100 ml. The corresponding values at CKD stage 5 were 23.7 (95% CI 2.666-210.583; p = 0.005) and 28.3 (95% CI 3.289-243.252; p = 0.002), respectively. Radiation (dose area product) was significantly higher in the CO₂-endovascular revascularization group (6.025 ± 6.926 cGy*cm² vs. 4.281 ± 4.722 cGy*cm², p = 0.009).

CONCLUSION

CO₂ is an applicable and safe alternative to iodinated contrast medium for endovascular revascularization in peripheral artery disease patients with concomitant CKD. Patients with CKD stage 4 or 5, being at highest risk for post-contrast AKI, should primarily be treated by CO₂-guided endovascular revascularization.

Outcome of patients with chronic limb-threatening ischemia with and without revascularization

Summary: Background: Patients with chronic critical limb-threatening ischemia (CLTI) are at high risk of amputation and death. Despite the general recommendation for revascularization in CTLI in the guidelines, the underlying evidence for such a recommendation is limited. The aim of our study was to assess the outcome of patients with CLTI depending on the use of revascularization in a retrospective real-world cohort. Patients and methods: Administrative data of the largest German Health insurance (BARMER GEK) were provided for all patients that were hospitalized for the treatment of CLTI Rutherford category (RF) 5 and 6 between 2009 and 2011. Patients were followed-up until December 31st, 2012 for limb amputation and death in relation to whether patients did (Rx +) or did not have (Rx −) revascularization during index-hospitalization. Results: We identified 15,314 patients with CLTI at RF5 (n = 6,908 (45.1%)) and RF6 (n = 8,406 (54.9%)), thereof 7,651 (50.0%) underwent revascularization (Rx +) and 7,663 (50.0%) were treated conservatively (Rx −). During follow-up (mean 647 days; 95% CI 640–654 days) limb amputation (46.5% Rx− vs. 40.6% Rx+, P < 0.001) and overall mortality (48.2% Rx− vs. 42.6% Rx+, P < 0.001) were significantly lower in the subgroup Rx+. Conclusions: In a real-world setting, only half of CLTI were revascularized during the in-hospital treatment. Though, revascularization was associated with significantly better observed short- and long-term outcome. These data do not allow causal conclusion due to lack of data on the underlying reason for applied or withheld revascularization and therefore may involve a relevant selection bias.

Impact of diabetes type on treatment and outcome of patients with peripheral artery disease

BACKGROUND

The prevalence of diabetes mellitus and its associated complications such as peripheral artery disease is increasing worldwide. We aimed to explore the distinct impact of type 1 diabetes mellitus and type 2 diabetes mellitus on treatment and on short- and long-term outcome in patients with peripheral artery disease.

METHODS

Retrospective analysis of anonymized data of hospitalized patients covered by a large German health insurance. Assessment of patient's characteristics (comorbidities, complications, etc.) and outcome using multivariable Cox regression and Kaplan-Meier curves.

RESULTS

Among 41,702 patients with peripheral artery disease, 339 (0.8%) had type 1 diabetes mellitus and 13,151 (31.5%) had type 2 diabetes mellitus. Patients with diabetes mellitus had more comorbidities and complications than patients without diabetes mellitus ( p < 0.001). Type 1 diabetes mellitus patients exhibited the highest risk for limb amputation at 4-year follow-up (44.6% vs 35.1%, p < 0.001), while type 2 diabetes mellitus patients had higher mortality than type 1 diabetes mellitus (43.6% vs 31.0%, p < 0.001).

CONCLUSION

Although the fraction of type 1 diabetes mellitus among patients with peripheral artery disease and diabetes mellitus is low, it represents a subset of patients being at particular high risk for limb amputation. Research focused on elaborating the determinants of limb amputation and mortality in peripheral artery disease patients with diabetes mellitus is warranted to improve the poor prognosis of these patients.

Nationwide Routine-Data Analysis of Sex Differences in Outcome of Acute Myocardial Infarction

Women have been reported to suffer from impaired outcome after acute myocardial infarction (AMI). The aim of our study was to determine the impact of sex and age on utilization of inpatient healthcare and outcome in patients with AMI (STEMI and NSTEMI) in a real-life setting. We performed a routine-data-based analysis of 203 106 nationwide inpatients hospitalized with STEMI and NSTEMI, focusing on sex differences regarding risk constellation, treatments, and in-hospital outcome. A logistic regression model was designed to evaluate the use of coronary angiography and interventions and their sex-related impact on mortality (within 30 days). Compared with males, female STEMI patients (25 146, vs 52 965 males) were older and had a higher incidence of diabetes mellitus (27.4% vs 20.6%), heart failure (32.8% vs 26.2%), and chronic kidney disease (19.1% vs 13.5%, respectively; all P < 0.05), and had higher observed in-hospital mortality (STEMI, 16.9% vs 9.9%; NSTEMI, 11.7% vs 8.7%). Females were less likely to receive coronary angiography in STEMI in the age groups <60 and ≥ 80 years (odds ratio: 0.8, 95% confidence interval: 0.76-0.83, P < 0.05), despite similar mortality risk reduction. Estimated overall in-hospital mortality showed no differences with respect to sex in STEMI for age groups 40 to 79 years. However, females age ≥ 80 years had slightly higher in-hospital mortality after adjustment. The increased observed in-hospital mortality in females was attributed to the impact of more unfavorable risk and age distribution. Coronary angiography was associated with lower in-hospital mortality; particularly, older females were less frequently treated.

Association of CKD with Outcomes Among Patients Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND AND OBJECTIVES

Despitethe multiple depicted associations of CKD with reduced cardiovascular and overall prognoses, the association of CKD with outcome of patients undergoing transcatheter aortic valve implantation has still not been well described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from all hospitalized patients who underwent transcatheter aortic valve implantation procedures between January 1, 2010 and December 31, 2013 in Germany were evaluated regarding influence of CKD, even in the earlier stages, on morbidity, in-hospital outcomes, and costs.

RESULTS

A total of 28,716 patients were treated with transcatheter aortic valve implantation. A total of 11,189 (39.0%) suffered from CKD. Patients with CKD were predominantly women; had higher rates of comorbidities, such as coronary artery disease, heart failure at New York Heart Association 3/4, peripheral artery disease, and diabetes; and had a 1.3-fold higher estimated logistic European System for Cardiac Operative Risk Evaluation value. In-hospital mortality was independently associated with CKD stage ≥3 (up to odds ratio, 1.71; 95% confidence interval, 1.35 to 2.17; P<0.05), bleeding was independently associated with CKD stage ≥4 (up to odds ratio, 1.82; 95% confidence interval, 1.47 to 2.24; P<0.001), and AKI was independently associated with CKD stages 3 (odds ratio, 1.83; 95% confidence interval, 1.62 to 2.06) and 4 (odds ratio, 2.33; 95% confidence interval, 1.92 to 2.83 both P<0.001). The stroke risk, in contrast, was lower for patients with CKD stages 4 (odds ratio, 0.23; 95% confidence interval, 0.16 to 0.33) and 5 (odds ratio, 0.24; 95% confidence interval, 0.15 to 0.39; both P<0.001). Lengths of hospital stay were, on average, 1.2-fold longer, whereas reimbursements were, on average, only 1.03-fold higher in patients who suffered from CKD.

CONCLUSIONS

This analysis illustrates for the first time on a nationwide basis the association of CKD with adverse outcomes in patients who underwent transcatheter aortic valve implantation. Thus, classification of CKD stages before transcatheter aortic valve implantation is important for appropriate risk stratification.

Rationale and design of the RECording COurses of vasculaR Diseases registry (RECCORD registry)

BACKGROUND

The prevalence of peripheral artery disease (PAD) is increasing worldwide. Revascularization procedures constitute a cornerstone of the therapy in PAD, not only in critical limb ischaemia but increasingly also in patients with intermittent claudication. The German Society of Angiology - Society for Vascular Medicine is establishing a nationwide, prospective, multicentre registry to address the lack of contemporary real life data regarding current practice of medical and interventional care in vascular patients and its subsequent long-term outcome.

PATIENTS AND METHODS

The RECording COurses of vasculaR Diseases registry (RECCORD registry) is an observational, prospective, multicentre, all-comers registry platform. In the initial phase, patients referred for endovascular revascularization of PAD of the lower limbs will be prospectively included and followed up for at least one year. At baseline, data on patients' demographic characteristics, comorbidities, previous peripheral interventions, medication, and clinical stage of PAD (Rutherford category), haemodynamic parameters, and procedural data including complications will be assessed. Major adverse cardiac and limb events will be recorded at planned (at six and 12 months) and at any unplanned visits. The therapeutic management will be exclusively left to the discretion of the vascular specialists.

RESULTS AND CONCLUSIONS

The RECCORD registry will provide a comprehensive dataset depicting the current real life practice and outcome of vascular care. The seven predefined quality indicators will be used for benchmarking the participating centres. Moreover, identifying factors promoting a favourable outcome might pave the way for an evidence-based therapeutic strategy and a dedicated therapeutic pathway for patients with PAD including patient-oriented best interventional approaches. In the future, the RECCORD registry may provide a general platform to study the courses of various defined vascular diseases in order to get detailed insights into the real life current practice of health care provided to vascular patients.

Impact of diabetes on outcome in critical limb ischemia with tissue loss: a large-scaled routine data analysis

BACKGROUND

Patients with diabetes concomitant to critical limb ischemia (CLI) represent a sub-group at particular risk. Objective of this analysis is to evaluate the actual impact of diabetes on treatment, outcome, and costs in a real-world scenario in Germany.

METHODS

We obtained routine-data on 15,332 patients with CLI with tissue loss from the largest German health insurance, BARMER GEK from 2009 to 2011, including a follow-up until 2013. Patient data were analyzed regarding co-diagnosis with diabetes with respect to risk profiles, treatment strategy, in-hospital and long-term outcome including costs.

RESULTS

Diabetic patients received less overall revascularizations in Rutherford grades 5 and 6 (Rutherford grade 5: 45.0 vs. 55.5%; Rutherford grade 6: 46.5 vs. 51.8; p < 0.001) and less vascular surgery (Rutherford grade 5: 13.4 vs. 23.4; Rutherford grade 6: 19.7 vs. 29.6; p < 0.001), however more often endovascular revascularization in Rutherford grade 6 (31.0 vs. 28.1; p = 0.004) compared to non-diabetic patients. Diabetes was associated with a higher observed ratio of infections (35.3 vs. 23.5% Rutherford grade 5; 44.3 vs. 27.4% Rutherford grade 6; p < 0.001) and in-hospital amputations (13.0 vs. 7.3% Rutherford grade 5; 47.5 vs. 36.7% Ruth6; p < 0.001). Diabetes further increased the risk for amputation during follow-up [Rutherford grade 5: HR 1.51 (1.38-1.67); Rutherford grade 6: HR 1.33 (1.25-1.41); p < 0.001], but not for death.

CONCLUSIONS

Diabetes increases markedly the risk of amputation attended by higher costs in CLI patients with tissue loss (OR 1.67 at Rutherford 5, OR 1.53 at Rutherford 6; p < 0.001), but is associated with lower revascularizations. However, in Rutherford grades 5 and 6, concomitant diabetes does not further worsen the overall poor survival.

Long-term mortality after invasive diagnostic and endovascular revascularization in PAD patients

BACKGROUND

The aim of this study was to assess the long-term, all-cause mortality among PAD patients hospitalized for invasive diagnostics and/or endovascular revascularization (ER) and the applied secondary prevention management.

METHODS

From 2005 to 2009, at our center 582 consecutive patients underwent invasive peripheral angiography in part in combination with coronary angiography and/or ER. Patients were classified according to their Fontaine stage into 3 subgroups: Fontaine I/IIa, Fontaine IIb, and Fontaine stages III and IV (which were classified as critical limb ischemia, CLI). Demographic and clinical data were retrospectively obtained and patients followed up.

RESULTS

Mean age increased with higher Fontaine stages (P=0.009). The proportion of patients with diabetes and anemia was lowest in Fontaine stage IIb and highest in CLI (each p<0.001). The cumulative all-cause mortality during follow-up was 17% in Fontaine stage I/IIa, 22% in Fontaine stage IIb and 34% in CLI, respectively (P<0.001). In multivariate cox regression models including diabetes mellitus, gender, age, creatinine and baseline hemoglobin, patients with Fontaine stage IIb had a 1.4-fold (95%CI 0.60-3.16) and those with CLI a 2.3-fold (95%CI 1.03-5.08) increased mortality compared to Fontaine stage I/IIa. At baseline, patients with CLI received significantly less beta blocker, statins, ACE or AT1 inhibitors and less anticoagulants; at follow-up only statins were significantly less often prescribed to CLI patients (all p<0.05). Univariate analyses showed that a therapy with statins (HR 0.64; CI 0.43-0.96; P=0.03) and antiplatelet/anticoagulant agents (HR 0.5; CI 0.27-0.94; P=0.03) significantly reduced mortality.

CONCLUSIONS

Long-term mortality in CLI patients doubles the rate in patients with Fontaine stage I/IIa. Non-adherence to evidence-based recommendations and guidelines such as inadequate use of cardioprotective drugs might contribute to the observed high mortality rates in patients with CLI.

Amputations and mortality in in-hospital treated patients with peripheral artery disease and diabetic foot syndrome

AIMS

The prevalence of diabetes mellitus (DM) and its associated complications such as peripheral artery disease (PAD) and diabetic foot syndrome (DFS) are increasing worldwide. We aimed to determine the contemporary acute and long-term outcome of patients with PAD and DFS in Germany.

METHODS

Nationwide, anonymized data of 40,335 patients hospitalized for PAD and/or DFS from the years 2009-2011 were analyzed and followed up until 2013. Patients were classified into 3 groups: DFS, PAD+DM and PAD without DM. In-hospital and long-term outcome (1156days, 95% CI 1.151-1.161) regarding major and minor amputation and mortality was assessed. Cumulative amputation-free survival and overall survival rates were calculated using Kaplan-Meier analysis.

RESULTS

The proportion of DFS, PAD+DM and PAD only was 17.3%, 21.5% and 61.2%, respectively. At index-hospitalization, DFS patients had the highest amputation (31.9% vs. 11.1% vs. 6.0%), yet the lowest revascularization rate (18.2% vs. 67.8% vs. 71.6%) compared to patients with PAD only and PAD+DM (P<0.001). Cumulative 4-year survival (57.4%, 60.8% and 70.0%) and amputation-free-survival (45.4%, 74.4% and 86.5%) were lowest for DFS followed by PAD+DM and PAD only (P<0.001).

CONCLUSIONS

Patients with diabetes, particularly those with DFS, have persistent high rates of limb amputation and of mortality in a real-world setting. Our data emphasize the need for further dedicated research to identify and target the underlying causes of the extraordinary poor outcome in this high risk population.

Low Rates of Revascularization and High In-Hospital Mortality in Patients With Ischemic Lower Limb Amputation

Background:

To assess the nationwide contemporary burden of cardiovascular risk factors, comorbidities, and in-hospital mortality in patients with lower limb amputation (LLA) due to peripheral arterial disease and critical limb ischemia (CLI) in Germany.

Methods:

German nationwide data for 2005 and 2009 were analyzed regarding in-hospital rates of major and minor ischemic LLA, risk factors, comorbidities, surgical and endovascular revascularizations, and in-hospital mortality.

Results:

In 2005, a total of 22 479 major (7.8%) and 28 262 minor (9.8%) LLAs were performed with a relative decrease of −21.8% in major LLA, yet with a relative increase of +2% in minor LLA rate in 2009. The overall revascularization rate before amputation was 46% in 2005 and 57% in 2009. In-hospital mortality for non-CLI, minor, and major amputees was 3.3%, 4.6%, and 19.8%, respectively ( P < .001 for major vs minor LLA and non-CLI).

Conclusion:

The total number of ischemic LLA and amputation-related in-hospital mortality remains high in Germany in the 21st century. The poor outcome of patients with CLI might in part be due to underuse of revascularizations prior to amputation.

The Impact of Chronic Kidney Disease on Hospitalized Patients With Peripheral Arterial Disease and Critical Limb Ischemia

Peripheral arterial disease (PAD) and chronic kidney disease (CKD) are major public health problems worldwide. Evaluations of large-scale data on morbidity, outcome, and costs in patients having PAD with CKD are essential. Cross-sectional nationwide population-based analysis of all hospitalizations for PAD during 2009 in Germany focused on the stage-related impact of CKD on morbidity, in-hospital mortality, amputations, length of hospital stay, and health-related expenditure. The total number of hospitalizations was 483 961. Of those, 132 993 (27.5%) had CKD. Chronic kidney disease caused 1.8-fold higher amputation rate ( P < .001) with a stepwise increasing rate with higher CKD stage. Chronic kidney disease doubled in-hospital mortality of patients with PAD (7.8%; n = 10 421) versus 4.0% (n = 14 174, P < .001) with a stepwise increasing risk with higher CKD stage ( P < .001). The highest in-hospital mortality occurred in patients with coprevalence of CKD stage 4 and Fontaine stage IV (16.4%, n = 1176, P < .001). Chronic kidney disease caused 15% higher costs and 21% increased length of stay compared to the whole PAD cohort. This analysis demonstrates the stage-related influence of CKD on morbidity, in-hospital mortality, amputations, length of hospital stay, and reimbursement costs of hospitalized patients with PAD.

Peripheral artery disease is associated with high in-hospital mortality particularly in males with acute myocardial infarction in a nationwide real-world setting

BACKGROUND

Patients with peripheral arterial disease (PAD) are at high risk for cardiovascular morbidity and mortality. The objective of this nationwide analysis was to explore the association of PAD with in-hospital mortality in patients hospitalized for acute myocardial infarction (AMI).

PATIENTS AND METHODS

Data on all in-patient hospitalizations in Germany are continuously transferred to the Federal Statistical Office (DESTATIS), as required by federal law. These case-based data on AMI in the years 2005, 2007 and 2009 were analyzed regarding ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) as the primary diagnoses and concomitant PAD as the secondary diagnosis with respect to age and gender related disparity.

RESULTS

We analyzed 619,103 AMI cases, including 270,026 (43.6 %) with STEMI and 349,077 (56.4 %) with NSTEMI. The PAD ratio was 3.4 % in STEMI and 5.7 % in NSTEMI. In STEMI, in-hospital mortality was 15.6 % in cases with PAD vs. 12.0 % without, and 12.0 % vs. 9.8 % in NSTEMI, respectively (P < 0.001; 2009). Although female gender was associated with a significantly higher in-hospital mortality, the presence of PAD particularly negatively affected in-hospital mortality in men (+ 60 % male vs - 11 % female in STEMI; + 33 % male vs - 3 % female in NSTEMI).

CONCLUSIONS

Our data demonstrate the adverse impact of concomitant PAD on in-hospital mortality in AMI, in a large-scale, real-world scenario. Further research, particularly with a focus on gender, is needed to identify diagnostic and therapeutic measures to reduce the remarkably high in-hospital mortality of AMI patients with concomitant PAD.

Acute and chronic anemia and short- and long-term outcome of patients with peripheral arterial disease and critical limb ischemia

BACKGROUND

Evident data about the additive effect of "the fifth cardiovascular risk factor" (anemia) and peripheral arterial disease (PAD) focused on morbidity and outcome of patients with PAD are currently still missing.

METHODS AND RESULTS

A total of 41,882 PAD patients were included. Of these, 5566 (13.3%) suffered from anemia. Patients with anemia were older (P<0.001), suffered more often from chronic kidney disease (P<0.001), coronary artery disease (P<0.001), and more severe PAD (P<0.001). However, they received significantly less endovascular revascularizations (P<0.001), had higher amputation rates (acute anemia: 3.7-fold, P<0.001; nutritional, aplastic, and anemia in chronic disease: 2.9-fold, P<0.001), higher in-hospital mortality rates (acute anemia: 6.4-fold, P<0.001; nutritional, aplastic, and anemia in chronic disease: 4.6-fold; P<0.001), had significantly higher in-hospital complications (P<0.001) compared to those without anemia. During a follow-up time up to 4years (until Dec. 31st, 2012, median 775days, 25th-75th percentiles 469-1120days) nutritional, aplastic, and anemia in chronic disease and acute anemia were high significant predictors of long-term mortality and amputation (each P<0.001). Lengths of hospital stay and reimbursement costs were higher (nutritional, aplastic, and anemia in chronic disease: 2-fold higher (P<0.001), acute anemia: 3-fold higher (P<0.001)) than in patients without anemia.

CONCLUSION

This study illustrates from a large, comprehensive database the association of acute, nutritional, aplastic, and anemia in chronic disease on morbidity, in-hospital treatment and complications, short- and long term outcome, and costs of patients with PAD.

CKD and Acute and Long-Term Outcome of Patients with Peripheral Artery Disease and Critical Limb Ischemia

BACKGROUND AND OBJECTIVES

Despite the many studies showing an association between CKD and a high risk of ischemic events and mortality, the association of CKD with peripheral arterial disease (PAD) still has not been well described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This large cohort study assessed the association of CKD, even in the earlier stages, with morbidity, short- and long-term outcome, and costs among patients with PAD.

RESULTS

We identified 41,882 patients with PAD who had an index hospitalization between January 1, 2009, and December 31, 2011. Of these, 8470 (20.2%) also had CKD (CKD stage 2: n=2158 [26%]; stage 3: n=3941 [47%]; stage 4: n=935 [11%]; stage 5: n=1436 [17%]). The ratio of women to men was 1:1.2. Compared with patients without known CKD, those with CKD had higher frequencies of coronary artery disease (1.8-fold higher; P<0.001), chronic heart failure (3.3-fold higher; P<0.001), and Rutherford PAD categories 5 and 6 (1.8-fold higher; P<0.001); underwent significantly fewer revascularizations (0.9-fold fewer; P<0.001); had a nearly two-fold higher amputation rate (P<0.001); had higher frequencies of in-hospital infections (2.1-fold higher; P<0.001), acute renal failure (2.8-fold higher; P<0.001), and sepsis (1.9-fold higher; P<0.001); had a 2.5-fold higher frequency of myocardial infarction (P<0.001); and had a nearly three-fold higher in-hospital mortality rate (P<0.001). In an adjusted multivariable Cox regression model, CKD remained a significant predictor of long-term outcome of patients with PAD during follow-up for up to 4 years (until December 31, 2012; median, 775 days; 25th-75th percentiles, 469-1120 days); the hazard ratio was 2.59 (95% confidence interval, 2.21 to 2.78; P<0.001). The projected mortality rates after 4 years were 27% in patients without known CKD and 46%, 52%, 72%, and 78% in those with CKD stages 2, 3, 4, and 5, respectively. Lengths of hospital stay and reimbursement costs were on average nearly 1.4-fold higher (P<0.001) in patients who also had CKD.

CONCLUSIONS

This analysis illustrates the significant and important association of CKD with in-hospital and long-term mortality, morbidity, amputation rates, duration and costs of hospitalization, in-hospital treatment, and complications in patients with PAD.

Outcome of patients with reduced ankle brachial index undergoing open heart surgery with cardiopulmonary bypass

OBJECTIVES

In open heart surgery using cardiopulmonary bypass, perfusion of the lower extremities is markedly reduced which may induce critical ischaemia in patients with pre-existing peripheral artery disease. Whether these patients have an increased risk for amputation and should better undergo peripheral revascularization prior to surgery remains unclear.

METHODS

From 1 January 2009 to 31 December 2010, 785 consecutive patients undergoing open heart surgery were retrospectively included. In 443 of these patients, preoperative ankle brachial index (ABI) measurements were available. The cohort was divided into four groups: (i) ABI < 0.5, (ii) ABI 0.5-0.69, (iii) ABI 0.7-0.89 or (iv) ABI ≥ 0.9. Follow-up data of 413 (93.2%) patients were analysed with regard to mortality and amputations.

RESULTS

The groups differed significantly in terms of age, cardiac risk factors, performed cardiac surgery and renal function. Postoperative delayed wound healing was significantly associated with lower ABI (25.9, 15.2, 27.0 and 9.6% in Groups I-IV, respectively, P = 0.003), whereas 30-day mortality was not significantly higher in patients with lower ABI (0, 4.3, 8.1 and 3.9%, respectively, P = 0.4). Kaplan-Meier models showed a significantly lower long-term survival over 4 years in patients with reduced ABI (P = 0.001, long-rank test) while amputations occurred rarely with only one minor amputation in Group II (P = 0.023).

CONCLUSIONS

Patients with reduced ABIs undergoing heart surgery showed more wound-healing disturbances, and higher long-term mortality compared with those with normal ABIs. However, no perioperative ischaemia requiring amputation occurred. Thus, reduced ABIs were not associated with increased peripheral risks in open heart surgery but ABI may be helpful in selecting the site for saphenectomy to potentially avoid delayed healing of related wounds in legs with severely impaired arterial perfusion.

Long-Term Mortality After Invasive Angiography and Endovascular Revascularization in Patients With PAD Having Chronic Kidney Disease

Peripheral arterial disease (PAD) and chronic kidney disease (CKD) are associated with increased mortality rates. We assessed long-term outcomes of patients with PAD and CKD. Patients with PAD undergoing invasive angiography and/or endovascular revascularization between 2005 and 2010 were retrospectively classified into 5 CKD stages. A follow-up was performed and 572 patients were included, 116 patients (20%) had normal renal function, 245 were in CKD stage 2 (43%), 156 in CKD stage 3 (27%), and 55 in CKD stages 4 + 5 (10%). Diabetes mellitus, hypertension, and anemia were more frequent in higher CKD stages ( P < .03). During follow-up (mean 1135 days; 95% confidence interval 1159-1259), cumulative mortality was 21% and increased with advanced CKD stages (9%, 16%, 29%, and 47%, respectively, P < .001). In multivariate Cox regression models, higher CKD stages were significantly associated with poor survival. Medication adherence for secondary prevention was significantly lower than recommended but irrespective of CKD stages. Kidney function is an independent predictor of worse long-term survival in patients with PAD. While standard medications were used less often than recommended, no differences between CKD stages were noted.

Restenosis after endovascular revascularization in peripheral artery disease

Abstract. Endovascular revascularization (EVR) plays a leading role in the therapy of peripheral artery disease. The acute success rates of EVR in all anatomic territories and of all TASC lesions are excellent (> 95%). However, the occurrence of restenoses after EVR such as percutaneous transluminal angioplasty and particularly after stenting, poses a substantial limitation to the success of the procedure. Influenced by patient’s comorbidities, the severity of arteriosclerotic disease, lesion length and morphology as well as the techniques and devices used for EVR, the long-term outcome of EVR deteriorates markedly from the aortoiliac to the infrapopliteal segments of the lower limbs. The development of drug-coated balloons and drug-eluting stents reduced the occurrence of restenosis leading to considerably improved primary patency rates in the femoropopliteal segments. This review aims to provide an overview about the underlying mechanisms and current relevance of the various options in the field of EVR with regard to the rate of restenosis.

Acute and mid-term outcomes after treatment of multiple, recurrent restenoses of the lower limb arteries

AIM

Recanalization of long segmental occlusions of femoropopliteal arteries can be achieved by angioplasty and implantation of nitinol stents with high procedural success rates. However, due to recurrent in-stent restenoses (ISR) some patients need repeated interventions and their intermediate success rates are uncertain.

METHODS

Patients who were treated in our center from March 2008 through February 2011 due to symptomatic ISR (as determined by Duplex sonography) were retrospectively included in the study. After endovascular treatment of their ISR, they were prospectively evaluated with regard to recurrent ISR of the target lesions.

RESULTS

A total of 36 limbs (=lesions) in 32 patients (69% male, mean age 69±9 years) were successfully treated by balloon-angioplasty. Adjunctive cutting balloons and drug eluting balloons were used in 78% and 8%, respectively. Mean follow-up was 326 days. Recurrent ISR occurred in 10 (28%) lesions, while 26 (78%) lesions showed no recurrence of ISR. In a multivariate logistic regression analysis, age, gender, cardiovascular risk factors, renal failure and medication with cilostazol were not significantly associated with recurrent ISR. Moreover, the number of previous interventions of the target lesions was not an independent predictor of recurrent ISR.

CONCLUSION

Patients with multiple recurrences of ISR seem to have the same prospects of acute and mid-term success for endovascular treatment as those with first presentation of ISR. However, this observation has to be confirmed by prospective, large scale studies with a longer follow-up period to determine the significance of endovascular intervention within the scope of different revascularization approaches for treatment of recurrent ISR.

Peripheral arterial disease and critical limb ischaemia: still poor outcomes and lack of guideline adherence

AIMS

Only few and historic studies reported a bad prognosis of peripheral arterial disease (PAD) and critical limb ischaemia (CLI). The contemporary state of treatment and outcomes should be assessed.

METHODS AND RESULTS

From the largest public health insurance in Germany, all in- and outpatient diagnosis and procedural data were retrospectively obtained from a cohort of 41 882 patients hospitalized due to PAD during 2009-2011, including a follow-up until 2013. Patients were classified in Rutherford categories 1-3 (n = 21 197), 4 (n = 5353), 5 (n = 6916), and 6 (n = 8416). The proportions of patients with classical risk factors such as hypertension, dyslipidaemia, and smoking declined with higher Rutherford categories (each P < 0.001) while diabetes, chronic kidney disease, and chronic heart failure increased (each P < 0.001). Angiographies and revascularizations were performed less often in advanced PAD (each P < 0.001). In-hospital amputations increased continuously from 0.5% in Rutherford 1-3 to 42% in Rutherford 6, as also myocardial infarctions, strokes, and deaths (each P < 0.001). Among 4298 amputated patients with CLI, 37% had not received any angiography or revascularization neither during index hospitalization nor the 24 months before. During follow-up (mean 1144 days), 7825 patients were amputated and 10 880 died. Kaplan-Meier models projected 4-year mortality risks of 18.9, 37.7, 52.2, and 63.5% in Rutherford 1-3, 4, 5, and 6, and for amputation of 4.6, 12.1, 35.3, and 67.3%, respectively. In multivariable Cox regression models, PAD categories were significant predictors of death, amputation, myocardial infarction, and stroke (each P < 0.001). Length of in-hospital stay (5.8 ± 6.7 days, 10.7 ± 11.1days, 15.2 ± 13.8 days and 22.1 ± 20.3 days; P < 0.001) and mean case costs (3662 ± 3186 €, 5316 ± 6139 €, 6021 ± 4892 €, and 8461 ± 8515 €; P < 0.001) increased continuously in Rutherford 1-3, 4, 5, and 6. While only 49% of the patients suffered from CLI, these produced 65% of in-hospital costs (141 million €), and 56% during follow-up (336 million €).

CONCLUSION

Regardless of recent advances in PAD treatment, current outcomes remain poor especially in CLI. Despite overwhelming evidence for reduction of limb loss by revascularization, CLI patients still received significantly less angiographies and revascularizations.

Autologous bone marrow mononuclear cell therapy improves symptoms in patients with end-stage peripheral arterial disease and reduces inflammation-associated parameters

BACKGROUND AIMS

The purpose of this study was to evaluate the effect of autologous bone marrow mononuclear cells (BM-MNCs) on symptoms and perfusion indices in severely symptomatic patients with peripheral arterial disease (PAD) without further option for endovascular or surgical revascularization.

METHODS

Only patients with severe symptomatic PAD (Fontaine class IIb-IV, Rutherford category 3-6) not amenable for revascularization were treated. Bone marrow from both cristae iliacae was harvested; MNCs were isolated by the Ficoll density-gradient method and transplanted by means of intra-arterial and intramuscular injection in the index limb. Functional (pain score, ulcer healing, maximum walking distance) and perfusion indices such as ankle-brachial-index and transcutaneous oxygen pressure were documented before and after BM-MNC therapy. Additionally, serum concentration of C-reactive protein and interleukin-6 were measured as markers of inflammation before and after BM-MNC treatment.

RESULTS

Sixteen consecutive patients (four women; mean age, 63.0 ± 13 years) were treated with a mean dose of 4.2 ± 2.2 × 10(8) BM-MNCs. At 6 months' follow-up, ankle-brachial-index, transcutaneous oxygen pressure and maximum walking distance significantly increased, whereas C-reactive protein and interleukin-6 conversely decreased (P < 0.01 versus baseline values), resulting in 88% limb salvage, 75% pain reduction and 71% complete wound healing and/or reduction of ulcer size. One major and one minor amputation were performed, both in patients with Rutherford category 6.

CONCLUSIONS

Autologous BM-MNC therapy in patients with end-stage PAD improves tissue perfusion indices and decreases markers of inflammation. If our observations could be confirmed by large-scale, randomized controlled trials, BM-MNC transplantation could become an alternative therapeutic option for patients with end-stage PAD.

Thrombembolic occlusion of crural arteries following transcatheter aortic valve implantation--successful endovascular recanalization using a thrombus aspiration device

Transcatheter aortic valve implantation (TAVI) has become an increasingly used alternative to conventional surgical valve replacement in patients with severe aortic valve stenosis (AS) and high operative risk. We here describe a case of a TAVI performed in local anesthesia causing intraprocedural thromboembolic occlusion of non-stenotic crural arteries and its immediate successful therapeutic management by means of endovascular recanalization using a thrombus aspiration device.

Relationship between surface area of nonperfused myocardium and extravascular extraction of contrast agent following coronary microembolization

Myocardial microvascular permeability and coronary sinus concentration of muscle metabolites have been shown to increase after myocardial ischemia due to epicardial coronary artery occlusion and reperfusion. However, their association with coronary microembolization is not well defined. This study tested the hypothesis that acute coronary microembolization increases microvascular permeability in the porcine heart. The left anterior descending perfusion territories of 34 anesthetized pigs (32 ± 3 kg) were embolized with equal volumes of microspheres of one of three diameters (10, 30, or 100 μm) and at three different doses for each size. Electron beam computed tomography (EBCT) was used to assess in vivo, microvascular extraction of a nonionic contrast agent (an index of microvascular permeability) before and after microembolization with microspheres at baseline and during adenosine infusion. A high-resolution three-dimensional microcomputed tomography (micro-CT) scanner was subsequently used to obtain ex vivo, the volume and corresponding surface area of the embolized myocardial islands within the perfusion territories of the microembolized coronary artery. EBCT-derived microvascular extraction of contrast agent increased within minutes after coronary microembolization (P < 0.001 vs. baseline and vs. control values). The increase in coronary microvascular permeability was highly correlated to the micro-CT-derived total surface area of the nonperfused myocardium (r = 0.83, P < 0.001). In conclusion, myocardial extravascular accumulation of contrast agent is markedly increased after coronary microembolization and its magnitude is in proportion to the surface area of the interface between the nonperfused and perfused territories.

Particle-induced osteolysis in three-dimensional micro-computed tomography

Small-animal models are useful for the in vivo study of particle-induced osteolysis, the most frequent cause of aseptic loosening after total joint replacement. Microstructural changes associated with particle-induced osteolysis have been extensively explored using two-dimensional (2D) techniques. However, relatively little is known regarding the 3D dynamic microstructure of particle-induced osteolysis. Therefore, we tested micro-computed tomography (micro-CT) as a novel tool for 3D analysis of wear debris-mediated osteolysis in a small-animal model of particle-induced osteolysis. The murine calvarial model based on polyethylene particles was utilized in 14 C57BL/J6 mice randomly divided into two groups. Group 1 received sham surgery, and group 2 was treated with polyethylene particles. We performed 3D micro-CT analysis and histological assessment. Various bone morphometric parameters were assessed. Regression was used to examine the relation between the results achieved by the two methods. Micro-CT analysis provides a fully automated means to quantify bone destruction in a mouse model of particle-induced osteolysis. This method revealed that the osteolytic lesions in calvaria in the experimental group were affected irregularly compared to the rather even distribution of osteolysis in the control group. This is an observation which would have been missed if histomorphometric analysis only had been performed, leading to false assessment of the actual situation. These irregularities seen by micro-CT analysis provide new insight into individual bone changes which might otherwise be overlooked by histological analysis and can be used as baseline information on which future studies can be designed.

Assessment of aortic valve area in aortic stenosis using cardiac magnetic resonance tomography: comparison with echocardiography

BACKGROUND

Cardiac magnetic resonance tomography (CMR) is a new imaging technique capable of imaging the aortic valve with high resolution. We assessed the aortic valve area (AVA) in patients with aortic stenosis (AS) using CMR and compared the results to those obtained by transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE).

METHODS

Forty-two patients (36% female, 71 +/- 8 years) symptomatic for AS underwent TTE followed by TEE to determine the AVA; the continuity equation was used with TTE and the planimetry technique with TEE. In 26 of these patients, the AVA was additionally obtained by CMR planimetry.

RESULTS

The mean AVA derived by TTE, TEE and CMR were 0.74 +/- 0.27, 0.87 +/- 25 and 0.97 +/- 0.30 cm(2), respectively. The mean absolute differences in AVA were 0.13 +/- 0.19 cm(2) for TTE vs. TEE, 0.21 +/- 0.25 cm(2) for TTE vs. CMR and 0.05 +/- 0.11 cm(2) for CMR vs. TEE.

CONCLUSION

There is a good agreement between CMR and the echocardiographic determination of the AVA. If multicenter, large-scale studies confirm these observations, CMR could serve as a noninvasive alternative to TTE/TEE for the assessment of AVA in AS.

Using Cardiac Magnetic Resonance Tomography for Assessment of Aortic Valve Area in Aortic Valve Stenosis

Calcified aortic valve stenosis (AS) is the most common valvular disease in the elderly population and constitutes a significant health and socioeconomic problem. Doppler echocardiography is the recommended diagnostic tool for the initial evaluation of AS. Transvalvular pressure gradients and aortic valve area have been used as quantitative parameters for grading the severity of AS, but the latter one is less susceptible to changes in flow dynamics and therefore considered the more independent and reliable parameter. The aortic valve area can be assessed directly by transesophageal echocardiography (TEE), which reflects the anatomic or geometric orifice area, or it can be calculated noninvasively by transthoracic echocardiography (TTE) using the continuity equation, or, invasively, by cardiac catheterization (CC) using the Gorlin formula, both reflecting the effective orifice area. Assessment of aortic valve area by TTE can be limited in some patients due to inadequate acoustic window. Similarly, TEE as a semi-invasive technique is not well tolerated by some patients and the planimetry is limited in patients with heavily calcified aortic valve leaflets. CC is an invasive procedure associated with a substantial risk of cerebral embolism and the Gorlin formula has been shown to be susceptible to changes in flow dynamics. Cardiac magnetic resonance tomography (CMR) is a new imaging technique capable of imaging the aortic valve with high resolution and has recently been used for assessment of the aortic valve area in AS. This review focuses on the feasibility of CMR for the assessment of aortic valve area in AS compared to current standard techniques and discusses some of the typical pitfalls and the sources for the discrepant results observed between the different techniques for assessment of the aortic valve area.

Large mobile thrombus in non-atherosclerotic thoracic aorta as the source of peripheral arterial embolism

The presence of thrombi in the atherosclerotic and/or aneurysmatic aorta with peripheral arterial embolism is a common scenario. Thrombus formation in a morphologically normal aorta, however, is a rare event. A 50 years old woman was admitted to the mergency department for pain, coldness, and anesthesia in the the left foot. She had a 25 years history of cigarette smoking, a history of postmenopausal hormone replacement therapy (HRT), hypercholesterolemia and hyperfibrinogenemia. An extensive serologic survey for hypercoagulability, including antiphospholipid antibodies, and vasculitis disorders was negative. Transesophageal echocardiography revealed a large, pedunculated and hypermobile thrombus attached to the aortic wall 5 cm distal of the left subclavian artery. The patient was admitted to the surgery department, where a 15 cm long fresh, parietal thrombus could be removed from the aorta showing no macroscopic wall lesions or any other morphologic abnormalities.

This case report demonstrates the possibility of evolving a large, pedunculated thrombus in a morphologically intact aorta in a postmenopausal woman with thrombogenic conditions such as hyperfibrinogenemia, hypercholesterolemia, smoking and HRT. For these patients, profiling the individual risk and weighing the benefits against the potential risks is warranted before prescribing HRT.

Relation of nonperfused myocardial volume and surface area to left ventricular performance in coronary microembolization

BACKGROUND

After occlusion of an epicardial artery, left ventricular (LV) dysfunction is closely related to the volume of nonperfused myocardium (NPM). The impact of coronary microembolization (ME) on LV function, however, is larger relative to the total volume of NPM. We hypothesized that the total surface area (SA), rather than the total volume, of NPM is the major determinant of ME-induced LV dysfunction.

METHODS AND RESULTS

We injected microspheres of 10-, 30-, or 100-microm diameter at each of 3 doses selectively into the left anterior descending coronary artery of 48 anesthetized pigs. Electron beam computed tomography (CT) was used to measure regional myocardial perfusion and changes in LV wall thickening (DeltaWT) and stroke volume (DeltaSV) after ME. At postmortem, a transmural "biopsy" of 1 to 2 cm3 of embolized myocardium was imaged by micro-CT, resulting in 3D images that provided volumes and SAs of the individual nonperfused foci. Additionally, in 9 pigs, creatine phosphokinase (CK) activity in embolized myocardium was measured as an index of washout of substances from the NPM. After ME, DeltaWT, DeltaSV, and CK washout were correlated more closely with the total SA (r=0.95, P<0.001; r=0.68, P<0.01; and r=0.88, P=0.01, respectively) than with the total NPM volume (r=0.59, P>0.05; 0.46, P>0.05; and r=0.69, P=0.04, respectively).

CONCLUSIONS

After coronary ME, LV dysfunction is more closely related to the total SA than to the total volume of nonperfused microregions in the myocardium.

Role of vasa vasorum in transendothelial solute transport in the coronary vessel wall: a study with cryostatic micro-CT

Using cryostatic microscopic computed tomography (micro-CT), we sought to determine the role of coronary vasa vasorum (VV) in transendothelial solute transport in arteries with normal and increased permeability due to high plasma cholesterol levels. In 6-mo-old pigs on a normal (n=23) and 2% high cholesterol (HC) diet (n=8), 2-cm segments of the proximal left anterior descending coronary arteries were removed in vivo after a selective injection of X-ray contrast solution. Harvesting of the specimens occurred at 0, 15, 25, 35, or 45 s after completion of the contrast injection. Specimens were snap frozen and scanned in our cryostatic micro-CT. The spatial distribution of contrast in the coronary artery wall was quantified using the CT images. Right coronary arteries were infused with Microfil to determine VV density (VV/mm2) and the cumulative lumen surface area (mm2/mm3). Transendothelial diffusion of contrast into the coronary vessel wall is a dynamic process starting at both the subintima and the adventitia. The subintimal opacification moves as a wave toward the adventitia, whereas the adventitial wave resolves. The coronary vessel wall in animals on a HC diet shows higher opacification than in normal coronary arteries without an increase of VV total luminal surface area. The loss of endothelial integrity in hypercholesterolemia significantly alters VV solute washin to, and washout from, the coronary artery wall.

Relationship between arterial diameter and perfused tissue volume in myocardial microcirculation: a micro-CT-based analysis

The volume of myocardial tissue that is perfused by an epicardial coronary artery has been shown to be predictably related to the diameter of the epicardial arterial lumen. However, to what extent the intramyocardial microvasculature follows the epicardial rules remains unclear. To explore the relationship between the diameter of coronary arterioles and their subsequent perfused myocardial volumes, we quantified the volume of nonperfused myocardium resulting from an embolized arteriole of a certain diameter. We injected a single dose of microspheres selected from one of nine possible microsphere combinations (10, 30, and 100 μm diameter, each at three possible doses) into the left anterior descending coronary and/or left circumflex arteries of seven anesthetized pigs. At postmortem, the coronary arteries were infused with a radiopaque silicon polymer. Embolized myocardium (1 cm3) was scanned with a microcomputerized tomography scanner and resulted in three-dimensional images that consisted of 20 μm/side cubic voxels and a subvolume of the specimen with 4 μm/side cubic voxels. Image analysis provided the number and volumes of myocardial perfusion defects for each size and dose of microspheres. The smallest individual myocardial perfusion defects, which correspond to the volume of myocardium perfused by a single embolized arteriole, were found to be 0.0004 ± 0.0002, 0.02 ± 0.004, and 0.62 ± 0.099 mm3 for the 10-, 30-, and 100-μm microspheres, respectively. The number of myocardial perfusion defects in the embolized myocardium was inversely related to the dose of the injected microspheres. This reflects a clustering behavior that is consistent with a random distribution process of the individual embolized perfusion defects.

Impact of coronary vasa vasorum functional structure on coronary vessel wall perfusion distribution

Noncoronary vasa vasorum have been described as networks of microvessels in the wall of arteries and veins. However, we have shown, using microcomputerized tomography (micro-CT) imaging methods, that porcine coronary vasa vasorum have a tree-like branching structure similar to the vasculature in general. In this study, we elucidate functional aspects of coronary vasa vasorum perfusion territories. Three pig hearts were injected with radiopaque Microfil via the coronary sinus to fill the left anterior descending coronary arteries (LADs) retrogradely at atmospheric pressure. In three other hearts, LADs were injected antegradely at 100-mmHg pressure via the left main carotid artery. Additionally, six LADs were injected in vivo with a suspension of 100- or 300-microm-diameter microspheres before harvesting of the hearts and injection of the LADs with Microfil. All harvested LADs were scanned intact with micro-CT (20 microm cubic voxels). The spatial density of vasa vasorum (no. of vasa/mm2) was measured in 20-microm-thick cross sections (at 0.4-mm intervals). Retrogradely injected LADs showed high and uniformly distributed vasa vasorum densities in the adventitia (means +/- SE; 5.38 +/- 0.09 vs. 3.58 +/- 0.1 vasa/mm2 in antegradely prepared LADs; P < 0.001). Antegradely prepared LADs showed patchy distributed, low-vasa-vasorum-density territories especially on the myocardial side of the coronary artery wall (epicardial density: 4.29 +/- 0.13 vasa/mm2 vs. myocardial density: 2.80 +/- 0.1 vasa/mm2, P < 0.001). Microembolization reduced vasa vasorum densities significantly (100-mum-diameter microspheres: 3.26 +/- 0.07 vasa/mm2, P < 0.05; 300-microm-diameter microspheres: 2.66 +/- 0.07 vasa/mm2, P < 0.001 vs. antegrade controls) and increased the size of low-vasa-vasorum-density territories. We conclude that coronary vasa vasorum are functional endarteries not connected via a plexus. This characteristic may have a significant impact on the spatial distribution of perfusion and drainage of the coronary vessel wall.

Functional anatomy and hemodynamic characteristics of vasa vasorum in the walls of porcine coronary arteries

In this study vasa vasorum in the walls of porcine coronary arteries were examined, using three-dimensional (3D) micro-CT scanning techniques. These techniques leave the 3D structure of the vasa vasorum tree intact and thus provide a much more direct view of this structure than is possible from conventional histological sections. The study demonstrates-for the first time, we believe-both the different types and the fine architecture of these vasa vasorum. Furthermore, with the use of automated tree analysis software, it was possible to obtain quantitative geometrical data on the 3D structure of vasa vasorum trees that have not previously been available. The results indicate that despite the restrictive topology of the space in which they are present, the branching architecture of the vasa vasorum trees, which we surveyed, is surprisingly similar to that of vasculature in general. The volume of vessel wall tissue perfused or drained by a vasa vasorum tree was found to correlate well with the cross-sectional area of the root segment of the vasa vasorum tree, and the luminal surface area corresponding to this volume was found to be comparable with the surface area of an early atherosclerotic lesion. This is consistent with earlier findings that the ligation or removal of vasa vasorum leads to atherogenesis.