Thrombin Generation Is Associated with Venous Thromboembolism Recurrence, but Not with Major Bleeding and Death in the Elderly: A Prospective Multicenter Cohort Study

It is currently unknown whether thrombin generation is associated with venous thromboembolism (VTE) recurrence, major bleeding, or mortality in the elderly. Therefore, our aim was to prospectively study the association between thrombin generation and VTE recurrence, major bleeding, and mortality in elderly patients with acute VTE. Consecutive patients aged ≥65 years with acute VTE were followed for 2 years, starting from 1 year after the index VTE. Primary outcomes were VTE recurrence, major bleeding, and mortality. Thrombin generation was assessed in 551 patients 1 year after the index VTE. At this time, 59% of the patients were still anticoagulated. Thrombin generation was discriminatory for VTE recurrence, but not for major bleeding and mortality in non-anticoagulated patients. Moreover, peak ratio (adjusted subhazard ratio 4.09, 95% CI, 1.12-14.92) and normalized peak ratio (adjusted subhazard ratio 2.18, 95% CI, 1.28-3.73) in the presence/absence of thrombomodulin were associated with VTE recurrence, but not with major bleeding and mortality after adjustment for potential confounding factors. In elderly patients, thrombin generation was associated with VTE recurrence, but not with major bleeding and/or mortality. Therefore, our study suggests the potential usefulness of thrombin generation measurement after anticoagulation completion for VTE to help identify among elderly patients those at higher risk of VTE recurrence.

Risk stratification of elderly patients with acute pulmonary embolism

BACKGROUND

Combining high-sensitivity cardiac Troponin T (hs-cTnT), NT-pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) may improve risk stratification of patients with pulmonary embolism (PE) beyond the PESI risk score.

METHODS

In the prospective multicentre SWITCO65+ study, we analysed 214 patients ≥ 65 years with a new submassive PE. Biomarkers and clinical information for the PESI risk score were ascertained within 1 day after diagnosis. Associations of hs-TnT, NT-proBNP, hs-CRP and the PESI risk score with the primary endpoint defined as 6-month mortality were assessed. The discriminative power of the PESI risk score and its combination with hs-cTnT, NT-proBNP and hs-CRP for 6-month mortality was compared using integrated discrimination improvement (IDI) index and net reclassification improvement (NRI).

RESULTS

Compared with the lowest quartile, patients in the highest quartile had a higher risk of death during the first 6 months for hs-cTnT (adjusted HR 10.22; 95% CI 1.79-58.34; P = 0.009) and a trend for NT-proBNP (adjusted HR 4.3; 95% CI 0.9-20.41; P = 0.067) unlike hs-CRP (adjusted HR 1.97; 95% CI 0.48-8.05; P = 0.344). The PESI risk score (c-statistic 0.77 (95% CI 0.69-0.84) had the highest prognostic accuracy for 6-month mortality, outperforming hs-cTnT, NT-proBNP and hs-CRP (c-statistics of 0.72, 0.72, and 0.54), respectively. Combining all three biomarkers had no clinically relevant impact on risk stratification when added to the PESI risk score (IDI = 0.067; 95% CI 0.012-0.123; P = 0.018; NRI = 0.101 95% CI -0.099-0.302; P = 0.321).

CONCLUSIONS

In elderly patients with PE, 6-month mortality can adequately be predicted by the PESI risk score alone.

A high Gas6 level in plasma predicts venous thromboembolism recurrence, major bleeding and mortality in the elderly: a prospective multicenter cohort study

Essentials Predictive ability of pro-hemostatic Gas6 for recurrent venous thromboembolism (VTE) is unknown. We measured Gas6 levels in 864 patients with VTE over 3 years. High Gas6 (> 157%) at diagnosis is associated with VTE recurrence, major bleeding and mortality. Gas6 plasma levels measured 12 months after the index VTE are discriminatory for VTE recurrence. SUMMARY: Background Growth arrest-specific gene 6 (Gas6) is a prohemostatic protein with an unknown predictive ability for recurrent venous thromboembolism (VTE). In the elderly, VTE results in higher mortality but does not have a higher rate of recurrence than in younger patients. Consequently, anticoagulation management in the elderly is challenging. Objective To prospectively investigate the performance of Gas6 in predicting VTE recurrence, major bleeding and mortality in the elderly. Methods Consecutive patients aged ≥ 65 years with acute VTE were followed for a period of 3 years. Primary outcomes were symptomatic VTE recurrence, major bleeding, and mortality. Plasma Gas6 was measured with ELISA. Results Gas6 levels were measured in 864 patients at the time of the index VTE (T1) and, in 70% of them, also 12 months later (T2). The Gas6 level at T1 was discriminatory for VTE recurrence (C-statistic, 0.56; 95% confidence interval [CI] 0.51-0.62), major bleeding (0.60, 95% CI 0.55-0.65) and mortality (0.69, 95% CI 0.65-0.73) up to 36 months. VTE recurrence up to 24 months after T2 was discriminated by the Gas6 level at T2 (0.62, 95% CI 0.54-0.71). High Gas6 levels (> 157%) and continuous Gas6 levels at T1 were associated with VTE recurrence up to 6 months and 12 months, respectively. Conclusions In elderly patients, a high Gas6 level is associated with higher risks of VTE recurrence, major bleeding, and death. These findings support further studies to assess the performance of Gas6 in adjusting the length of anticoagulation.

Stellenwert der bildgebenden Sonographie und Duplex-Sonographie für die Diagnostik der Venenthrombose

Mit der Duplex-Sonographie steht eine neue, nichtinvasive Untersuchungsmethode zur Diagnose der tiefen Venenthrombose zur Verfügung. Die gezielte Venenkompression durch die Schallsonde des konventionellen Ultraschallgerätes erlaubt bereits in vielen Fällen die Diagnose, die zusätzliche Ableitung gepulster Doppler-Signale verbessert jedoch die diagnostische Aussagekraft beträchtlich. Die Einführung der farbkodierten Duplex-Sonographie hat die Untersuchungstechnik erleichtert und zur derzeitigen Beliebtheit beigetragen. 35 Studien mit insgesamt 4747 phlebographisch kontrollierten Extremitäten berichten durchwegs über eine hohe Sensitivität (Median 95%) und Spezifität (Median 97%). Bei isolierter Unterschenkelvenenthrombose sind Sensitivität (89%) und Spezifität (92%) weniger günstig. Die diagnostische Treffsicherheit ist signifikant besser als mit den konventionellen nichtinvasiven Untersuchungstechniken (Plethysmographie, CW-Doppler), ist jedoch vergleichbar mit jener der invasiven Phlebographie. Die Duplex-Sonographie ist der Phlebographie in verschiedenen klinischen Situationen, ebenso wie bei der differentialdiagnostischen Abgrenzung, überlegen. Im Gegensatz zum Einsatz bei klinischem Verdacht auf TVT hat sich die Duplex-Sonographie jedoch als ScreeningMethode noch nicht eindeutig bestätigen können.

Comparative Performance of Clinical Risk Assessment Models for Hospital-Acquired Venous Thromboembolism in Medical Patients

BACKGROUND

Improved thromboprophylaxis for acutely ill medical patients relies on valid predictions of thrombotic risks. Our aim was to compare the performance of the Improve and Geneva clinical risk assessment models (RAMs), and to simplify the current Geneva RAM.

METHODS

Medical inpatients from eight Swiss hospitals were prospectively followed during 90 days, for symptomatic venous thromboembolism (VTE) or VTE-related death. We compared discriminative performance and calibration of the RAMs, using time-to-event methods with competing risk modelling of non-VTE death.

RESULTS

In 1,478 patients, the 90-day VTE cumulative incidence was 1.6%. Discrimination of the Improve and Geneva RAM was similar, with a 30-day AUC (areas under the curve) of 0.78 (95% CI [confidence interval]: 0.65-0.92) and 0.81 (0.73-0.89), respectively. According to the Improve RAM, 68% of participants were at low risk (0.8% VTE at 90 days), and 32% were at high risk (4.7% VTE), with a sensitivity of 73%. According to the Geneva RAM, 35% were at low risk (0.6% VTE) and 65% were at high risk (2.8% VTE), with a sensitivity of 90%. Among patients without thromboprophylaxis, the sensitivity was numerically greater in the Geneva RAM (85%) than in the Improve RAM (54%). We derived a simplified Geneva RAM with comparable discrimination and calibration as the original Geneva RAM.

CONCLUSIONS

We found comparably good discrimination of the Improve and Geneva RAMs. The Improve RAM classified more patients as low risk, but with possibly lower sensitivity and greater VTE risks, suggesting that a lower threshold for low risk (<2) should be used. The simplified Geneva RAM may represent an alternative to the Geneva RAM with enhanced usability.

Long-term anticoagulation treatment for acute venous thromboembolism in patients with and without cancer

In patients with acute cancer-associated thrombosis, current consensus guidelines recommend anticoagulation therapy for an indefinite duration or until the cancer is resolved. Among 1,247 patients with acute venous thromboembolism (VTE) enrolled in the prospective Swiss Venous Thromboembolism Registry (SWIVTER) II from 18 hospitals, 315 (25%) had cancer of whom 179 (57%) had metastatic disease, 159 (50%) ongoing or recent chemotherapy, 83 (26%) prior cancer surgery, and 63 (20%) recurrent VTE. Long-term anticoagulation treatment for >12 months was more often planned in patients with versus without cancer (47% vs. 19%; p<0.001), with recurrent cancer-associated versus first cancer-associated VTE (70% vs. 41%; p<0.001), and with metastatic versus non-metastatic cancer (59% vs. 31%; p<0.001). In patients with cancer, recurrent VTE (OR 3.46; 95%CI 1.83–6.53), metastatic disease (OR 3.04; 95%CI 1.86–4.97), and the absence of an acute infection (OR 3.55; 95%CI 1.65–7.65) were independently associated with the intention to maintain anticoagulation for >12 months. In conclusion, long-term anticoagulation treatment for more than 12 months was planned in less than half of the cancer patients with acute VTE. The low rates of long-term anticoagulation in cancer patients with a first episode of VTE and in patients with non-metastatic cancer require particular attention.

Predictors of thromboprophylaxis in hospitalised medical patients

Both, underuse and overuse of thromboprophylaxis in hospitalised medical patients is common. We aimed to explore clinical factors associated with the use of pharmacological or mechanical thromboprophylaxis in acutely ill medical patients at high (Geneva Risk Score ≥ 3 points) vs low (Geneva Risk Score < 3 points) risk of venous thromboembolism. Overall, 1,478 hospitalised medical patients from eight large Swiss hospitals were enrolled in the prospective Explicit ASsessment of Thromboembolic RIsk and Prophylaxis for Medical PATients in SwitzErland (ESTIMATE) cohort study. The study is registered on ClinicalTrials. gov, number NCT01277536. Thromboprophylaxis increased stepwise with increasing Geneva Risk Score (p< 0.001). Among the 962 high-risk patients, 366 (38 %) received no thromboprophylaxis; cancer-associated thrombocytopenia (OR 4.78, 95 % CI 2.75–8.31, p< 0.001), active bleeding on admission (OR 2.88, 95 % CI 1.69–4.92, p< 0.001), and thrombocytopenia without cancer (OR 2.54, 95 % CI 1.31–4.95, p=0.006) were independently associated with the absence of prophylaxis. The use of thromboprophylaxis declined with increasing severity of thrombocytopenia (p=0.001). Among the 516 low-risk patients, 245 (48 %) received thromboprophylaxis; none of the investigated clinical factors predicted its use. In conclusion, in acutely ill medical patients, bleeding and thrombocytopenia were the most important factors for the absence of thromboprophylaxis among highrisk patients. The use of thromboprophylaxis among low-risk patients was inconsistent, without clearly identifiable predictors, and should be addressed in further research.

Cardiac troponin testing and the simplified Pulmonary Embolism Severity Index

A low simplified Pulmonary Embolism Severity Index (sPESI), defined as age ≤80 years and absence of systemic hypotension, tachycardia, hypoxia, cancer, heart failure, and lung disease, identifies low-risk patients with acute pulmonary embolism (PE). It is unknown whether cardiac troponin testing improves the prediction of clinical outcomes if the sPESI is not low. In the prospective Swiss Venous Thromboembolism Registry, 369 patients with acute PE and a troponin test (conventional troponin T or I, highly sensitive troponin T) were enrolled from 18 hospitals. A positive test result was defined as a troponin level above the manufacturers assay threshold. Among the 106 (29%) patients with low sPESI, the rate of mortality or PE recurrence at 30 days was 1.0%. Among the 263 (71%) patients with high sPESI, 177 (67%) were troponin-negative and 86 (33%) troponin-positive; the rate of mortality or PE recurrence at 30 days was 4.6% vs. 12.8% (p=0.015), respectively. Overall, risk assessment with a troponin test (hazard ratio [HR] 3.39, 95% confidence interval [CI] 1.38–8.37; p=0.008) maintained its prognostic value for mortality or PE recurrence when adjusted for sPESI (HR 5.80, 95%CI 0.76–44.10; p=0.09). The combination of sPESI with a troponin test resulted in a greater area under the receiver-operating characteristic curve (HR 0.72, 95% CI 0.63–0.81) than sPESI alone (HR 0.63, 95% CI 0.57–0.68) (p=0.023). In conclusion, although cardiac troponin testing may not be required in patients with a low sPESI, it adds prognostic value for early death and recurrence for patients with a high sPESI.

Multicentre validation of the Geneva Risk Score for hospitalised medical patients at risk of venous thromboembolism

There is a need to validate risk assessment tools for hospitalised medical patients at risk of venous thromboembolism (VTE). We investigated whether a predefined cut-off of the Geneva Risk Score, as compared to the Padua Prediction Score, accurately distinguishes low-risk from high-risk patients regardless of the use of thromboprophylaxis. In the multicentre, prospective Explicit ASsessment of Thromboembolic RIsk and Prophylaxis for Medical PATients in SwitzErland (ESTIMATE) cohort study, 1,478 hospitalised medical patients were enrolled of whom 637 (43%) did not receive thromboprophylaxis. The primary endpoint was symptomatic VTE or VTE-related death at 90 days. The study is registered at ClinicalTrials.gov, number NCT01277536. According to the Geneva Risk Score, the cumulative rate of the primary endpoint was 3.2% (95% confidence interval [CI] 2.2–4.6%) in 962 high-risk vs 0.6% (95% CI 0.2–1.9%) in 516 low-risk patients (p=0.002); among patients without prophylaxis, this rate was 3.5% vs 0.8% (p=0.029), respectively. In comparison, the Padua Prediction Score yielded a cumulative rate of the primary endpoint of 3.5% (95% CI 2.3–5.3%) in 714 high-risk vs 1.1% (95% CI 0.6–2.3%) in 764 lowrisk patients (p=0.002); among patients without prophylaxis, this rate was 3.2% vs 1.5% (p=0.130), respectively. Negative likelihood ratio was 0.28 (95% CI 0.10–0.83) for the Geneva Risk Score and 0.51 (95% CI 0.28–0.93) for the Padua Prediction Score. In conclusion, among hospitalised medical patients, the Geneva Risk Score predicted VTE and VTE-related mortality and compared favourably with the Padua Prediction Score, particularly for its accuracy to identify low-risk patients who do not require thromboprophylaxis.

Long-term outcomes of elderly patients with CYP2C9 and VKORC1 variants treated with vitamin K antagonists

Essentials The long-term effects of VKORC1 and CYP2C9 variants on clinical outcomes remains unclear. We followed 774 patients ≥65 years with venous thromboembolism for a median duration of 30 months. Patients with CYP2C9 variants are at increased risk of death and non-major bleeding. Patients with genetic variants have a slightly lower anticoagulation quality only.

SUMMARY

Background The long-term effect of polymorphisms of the vitamin K-epoxide reductase (VKORC1) and the cytochrome P450 enzyme gene (CYP2C9) on clinical outcomes remains unclear. Objectives We examined the association between CYP2C9/VKORC1 variants and long-term clinical outcomes in a prospective cohort study of elderly patients treated with vitamin K antagonists for venous thromboembolism (VTE). Methods We followed 774 consecutive patients aged ≥ 65 years with acute VTE from nine Swiss hospitals for a median duration of 30 months. The median duration of initial anticoagulant treatment was 9.4 months. The primary outcome was the time to any clinical event (i.e. the composite endpoint of overall mortality, major and non-major bleeding, and recurrent VTE. Results Overall, 604 (78%) patients had a CYP2C9 or VKORC1 variant. Three hundred and thirty-four patients (43.2%) had any clinical event, 119 (15.4%) died, 100 (12.9%) had major and 167 (21.6%) non-major bleeding, and 100 had (12.9%) recurrent VTE. After adjustment, CYP2C9 (but not VKORC1) variants were associated with any clinical event (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.08-1.66), death (HR, 1.74; 95% CI, 1.19-2.52) and clinically relevant non-major bleeding (sub-hazard ratio [SHR], 1.39; 95% CI, 1.02-1.89), but not with major bleeding (SHR, 1.03; 95% CI, 0.69-1.55) or recurrent VTE (SHR, 0.95; 95% CI, 0.62-1.44). Patients with genetic variants had a slightly lower anticoagulation quality. Conclusions CYP2C9 was associated with long-term overall mortality and non-major bleeding. Although genetic variants were associated with a slightly lower anticoagulation quality, there was no relationship between genetic variants and major bleeding or VTE recurrence.

Derivation and validation of a novel bleeding risk score for elderly patients with venous thromboembolism on extended anticoagulation

Existing clinical scores do not perform well in predicting bleeding in elderly patients with acute venous thromboembolism (VTE). We sought to derive an easy-to-use clinical score to help physicians identify elderly patients with VTE who are at high-risk of bleeding during extended anticoagulation (>3 months). Our derivation sample included 743 patients aged ≥65 years with VTE who were enrolled in a prospective multicenter cohort study. All patients received extended anticoagulation with vitamin K antagonists. We derived our score using competing risk regression, with the time to a first major bleeding up to 36 months of extended anticoagulation as the outcome, and 17 candidate variables as predictors. We used bootstrapping methods for internal validation. Sixty-six (9 %) patients suffered major bleeding. The clinical score is based on seven clinical factors (previous bleeding, active cancer, low physical activity, anemia, thrombocytopenia, antiplatelet drugs/NSAIDs, and poor INR control). Overall, 48 % of patients were classified as low-risk, 37 % as moderate-risk, and 15 % as high-risk of bleeding. The rate of major bleeding was 1.4 events in low-risk, 5.0 events in moderate-risk, and 12.2 events per 100 patient-years in high-risk patients. The c-statistic was 0.78 at 3 months and 0.71 at 36 months of extended anticoagulation. Model calibration was excellent (p=0.93). Internal validation showed similar results. This simple clinical score accurately identified elderly patients with VTE who are at high risk of major bleeding and who may not benefit from extended anticoagulation. Further validation of the score is important before its implementation into practice. The study is registered to https://clinicaltrials.gov as NCT00973596.

The Modified Ottawa Score and Clinical Events in Hospitalized Patients with Cancer-Associated Thrombosis from the Swiss VTE Registry

The modified Ottawa score (MOS) predicted venous thromboembolism (VTE) recurrence in a cohort of patients with cancer-associated thrombosis mainly managed on an outpatient basis. We aimed to assess the prognostic value of the MOS in hospitalized patients with cancer-associated thrombosis. In 383 hospitalized patients with cancer-associated VTE from the SWIss VTE Registry, 98 (25%) were classified as low risk, 175 (46%) as intermediate risk, and 110 (29%) as high risk for VTE recurrence based on the MOS. Clinical end points were recurrent VTE, fatal VTE, major bleeding, and overall mortality at 90 days. Overall, 179 (47%) patients were female, 172 (45%) had metastatic disease, and 72 (19%) prior VTE. The primary site of cancer was lung in 48 (13%) patients and breast in 43 (11%). According to the MOS, the rate of VTE recurrence was 4.1% for low, 6.3% intermediate, and 5.5% high risk (p = 0.75); the rate of fatal VTE was 0.8, 1.9, and 2.0% (p = 0.69); the rate of major bleeding was 3.1, 4.1, and 3.6% (p = 0.92); and the rate of death was 6.1, 12.0, and 28.2% (p < 0.001), respectively. None of the MOS items was associated with VTE recurrence: female gender hazard ratio (HR) 1.26 (95% confidence interval [CI], 0.53–2.96), lung cancer HR 1.17 (95% CI, 0.35–3.98), prior VTE HR 0.44 (95% CI, 0.10–1.91), breast cancer HR 0.83 (95% CI, 0.19–3.58), and absence of metastases HR 0.74 (95% CI, 0.31–1.74). In hospitalized patients with cancer-associated VTE, the MOS failed to predict VTE recurrence at 3 months but was associated with early mortality.

Predictors and Causes of Long-Term Mortality in Elderly Patients with Acute Venous Thromboembolism: A Prospective Cohort Study

BACKGROUND

Long-term predictors and causes of death are understudied in elderly patients with acute venous thromboembolism.

METHODS

We prospectively followed up 991 patients aged ≥65 years with acute venous thromboembolism in a multicenter Swiss cohort study. The primary outcome was overall mortality. We explored the association between patient baseline characteristics and mortality, adjusting for other baseline variables and periods of anticoagulation as a time-varying covariate. Causes of death over time were adjudicated by a blinded, independent committee.

RESULTS

The median age was 75 years. During a median follow-up period of 30 months, 206 patients (21%) died. Independent predictors of overall mortality were age (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.05-1.65, per decade), active cancer (HR, 5.80; 95% CI, 4.22-7.97), systolic blood pressure <100 mm Hg (HR, 2.77; 95% CI, 1.56-4.92), diabetes mellitus (HR, 1.50; 95% CI, 1.02-2.22), low physical activity level (HR, 1.92; 95% CI, 1.38-2.66), polypharmacy (HR, 1.41; 95% CI, 1.01-1.96), anemia (HR, 1.48; 95% CI, 1.07-2.05), high-sensitivity C-reactive protein >40 mg/L (HR, 1.88; 95% CI, 1.36-2.60), ultra-sensitive troponin >14 pg/mL (HR, 1.54; 95% CI, 1.06-2.25), and D-dimer >3000 ng/mL (HR, 1.45; 95% CI, 1.04-2.01). Cancer (34%), pulmonary embolism (18%), infection (17%), and bleeding (6%) were the most common causes of death.

CONCLUSIONS

Elderly patients with acute venous thromboembolism have a substantial long-term mortality, and several factors, including polypharmacy and a low physical activity level, are associated with long-term mortality. Cancer, pulmonary embolism, infections, and bleeding are the most common causes of death in the elderly with venous thromboembolism.

Rivaroxaban for the treatment of venous thromboembolism. The SWIss Venous ThromboEmbolism Registry (SWIVTER)

We investigated three-month clinical outcomes in patients with venous thromboembolism (VTE) treated with rivaroxaban or conventional anticoagulation in routine clinical practice. Between November 2012 and February 2015, 2,062 consecutive patients with VTE from 11 acute care hospitals in Switzerland were enrolled in the SWIss Venous ThromboEmbolism Registry (SWIVTER). Overall, 417 (20 %) patients were treated with rivaroxaban. In comparison to 1,645 patients on conventional anticoagulation, patients on rivaroxaban were younger (56 ± 18 vs. 65 ± 17 years; p<0.001), less often had pulmonary embolism (38 % vs 66 %; p<0.001), hypertension (26 % vs 41 %; p<0.001), cancer (10 % vs 28 %; p<0.001), congestive heart failure (10 % vs 17 %; p=0.001), diabetes (8 % vs 15 %; p<0.001), chronic lung disease (7 % vs 13 %; p=0.001), renal insufficiency (7 % vs 13 %; p=0.001), recent surgery (7 % vs 14 %; p<0.001), and acute coronary syndrome (1 % vs 4 %; p=0.009). VTE reperfusion therapy was more frequently used (28 % vs 9 %; p<0.001) and indefinite-duration anticoagulation treatment less often planned (26 % vs 39 %; p<0.001), respectively. In the propensity score-adjusted population, the risk of recurrent VTE was similar in patients on rivaroxaban vs conventional anticoagulation (1.2 % vs 2.1 %, hazard ratio [HR] 0.55, 95 % confidence interval [CI] 0.18-1.65; p=0.29); the risk of major bleeding was also similar, respectively (0.5 % vs 0.5 %, HR 1.00, 95 %CI 0.14-7.07; p=1.00). Conventional anticoagulation is still frequently used for the treatment of VTE, particularly in the elderly and those with comorbidities. Early clinical outcomes were comparable between propensity score-adjusted patient populations on rivaroxaban and conventional anticoagulation.

Association between thyroid dysfunction and venous thromboembolism in the elderly: a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) and subclinical thyroid dysfunction (SCTD) are both common in elderly patients. SCTD has been related to a hypercoagulable state and an increased thromboembolic risk. However, prospective data on the relationship between SCTD and VTE are lacking.

OBJECTIVES

To investigate the relationship between SCTD and recurrent VTE (rVTE), all-cause mortality, and thrombophilic biomarkers. Patients Elderly patients with VTE were studied.

METHODS

In a prospective multicenter cohort, thyroid hormones and thrombophilic biomarkers were measured 1 year after acute VTE, as both may be influenced by acute thrombosis. We defined subclinical hypothyroidism (SHypo) as elevated thyroid-stimulating hormone (TSH) levels (4.50-19.99 mIU L(-1) ), and subclinical hyperthyroidism (SHyper) as TSH levels of < 0.45 mIU L(-1) , both with normal free thyroxine levels. Outcomes were incidence of rVTE and overall mortality during follow-up starting after the 1-year blood sampling.

RESULTS

Of 561 participants (58% with anticoagulation), 6% had SHypo and 5% had SHyper. After 20.8 months of mean follow-up, 9% developed rVTE and 10% died. The rVTE incidence rate was 7.2 (95% confidence interval [CI] 2.7-19.2) per 100 patient-years in SHypo participants, 0.0 (95% CI 0.0-7.6) in SHyper participants, and 5.9 (95% CI 4.4-7.8) in euthyroid participants. In multivariate analyses, the sub-hazard ratio for rVTE was 0.00 (95% CI 0.00-0.58) in SHyper participants and 1.50 (95% CI 0.52-4.34) in SHypo participants as compared with euthyroid participants, without increased levels of thrombophilic biomarkers. SHyper (hazard ratio [HR] 0.80, 95% CI 0.23-2.81) and SHypo (HR 0.99, 95% CI 0.30-3.29) were not associated with mortality.

CONCLUSION

In elderly patients, SHyper may be associated with lower rVTE risks. SHypo showed a non-statistically significant pattern of an association with rVTE, without increased mortality or differences in thrombophilic biomarkers.

Anticoagulation Management Practices and Outcomes in Elderly Patients with Acute Venous Thromboembolism: A Clinical Research Study

Whether anticoagulation management practices are associated with improved outcomes in elderly patients with acute venous thromboembolism (VTE) is uncertain. Thus, we aimed to examine whether practices recommended by the American College of Chest Physicians guidelines are associated with outcomes in elderly patients with VTE. We studied 991 patients aged ≥65 years with acute VTE in a Swiss prospective multicenter cohort study and assessed the adherence to four management practices: parenteral anticoagulation ≥5 days, INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulation, early start with vitamin K antagonists (VKA) ≤24 hours of VTE diagnosis, and the use of low-molecular-weight heparin (LMWH) or fondaparinux. The outcomes were all-cause mortality, VTE recurrence, and major bleeding at 6 months, and the length of hospital stay (LOS). We used Cox regression and lognormal survival models, adjusting for patient characteristics. Overall, 9% of patients died, 3% had VTE recurrence, and 7% major bleeding. Early start with VKA was associated with a lower risk of major bleeding (adjusted hazard ratio 0.37, 95% CI 0.20–0.71). Early start with VKA (adjusted time ratio [TR] 0.77, 95% CI 0.69–0.86) and use of LMWH/fondaparinux (adjusted TR 0.87, 95% CI 0.78–0.97) were associated with a shorter LOS. An INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulants was associated with a longer LOS (adjusted TR 1.2, 95% CI 1.08–1.33). In elderly patients with VTE, the adherence to recommended anticoagulation management practices showed mixed results. In conclusion, only early start with VKA and use of parenteral LMWH/fondaparinux were associated with better outcomes.

Physical activity and risk of bleeding in elderly patients taking anticoagulants

BACKGROUND

Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain.

OBJECTIVES

To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants.

PATIENTS/METHODS

In a prospective multicenter cohort study of 988 patients aged ≥ 65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding by using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate.

RESULTS

During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95% confidence interval 0.22-0.72). There was no association between physical activity and non-major bleeding.

CONCLUSIONS

A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy.

Polypharmacy is associated with an increased risk of bleeding in elderly patients with venous thromboembolism

BACKGROUND

Polypharmacy, defined as the concomitant use of multiple medications, is very common in the elderly and may trigger drug-drug interactions and increase the risk of falls in patients receiving vitamin K antagonists.

OBJECTIVE

To examine whether polypharmacy increases the risk of bleeding in elderly patients who receive vitamin K antagonists for acute venous thromboembolism (VTE).

DESIGN

We used a prospective cohort study.

PARTICIPANTS

In a multicenter Swiss cohort, we studied 830 patients aged ≥ 65 years with VTE.

MAIN MEASURES

We defined polypharmacy as the prescription of more than four different drugs. We assessed the association between polypharmacy and the time to a first major and clinically relevant non-major bleeding, accounting for the competing risk of death. We adjusted for known bleeding risk factors (age, gender, pulmonary embolism, active cancer, arterial hypertension, cardiac disease, cerebrovascular disease, chronic liver and renal disease, diabetes mellitus, history of major bleeding, recent surgery, anemia, thrombocytopenia) and periods of vitamin K antagonist treatment as a time-varying covariate.

KEY RESULTS

Overall, 413 (49.8 %) patients had polypharmacy. The mean follow-up duration was 17.8 months. Patients with polypharmacy had a significantly higher incidence of major (9.0 vs. 4.1 events/100 patient-years; incidence rate ratio [IRR] 2.18, 95 % confidence interval [CI] 1.32-3.68) and clinically relevant non-major bleeding (14.8 vs. 8.0 events/100 patient-years; IRR 1.85, 95 % CI 1.27-2.71) than patients without polypharmacy. After adjustment, polypharmacy was significantly associated with major (sub-hazard ratio [SHR] 1.83, 95 % CI 1.03-3.25) and clinically relevant non-major bleeding (SHR 1.60, 95 % CI 1.06-2.42).

CONCLUSIONS

Polypharmacy is associated with an increased risk of both major and clinically relevant non-major bleeding in elderly patients receiving vitamin K antagonists for VTE.

Risk of falls and bleeding in elderly patients with acute venous thromboembolism

OBJECTIVE

Whether or not a high risk of falls increases the risk of bleeding in patients receiving anticoagulants remains a matter of debate.

METHODS

We conducted a prospective cohort study involving 991 patients ≥ 65 years of age who received anticoagulants for acute venous thromboembolism (VTE) at nine Swiss hospitals between September 2009 and September 2012. The study outcomes were as follows: the time to a first major episode of bleeding; and clinically relevant nonmajor bleeding. We determined the associations between the risk of falls and the time to a first episode of bleeding using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate.

RESULTS

Four hundred fifty-eight of 991 patients (46%) were at high risk of falls. The mean duration of follow-up was 16.7 months. Patients at high risk of falls had a higher incidence of major bleeding (9.6 vs. 6.6 events/100 patient-years; P = 0.05) and a significantly higher incidence of clinically relevant nonmajor bleeding (16.7 vs. 8.3 events/100 patient-years; P < 0.001) than patients at low risk of falls. After adjustment, a high risk of falls was associated with clinically relevant nonmajor bleeding [subhazard ratio (SHR) = 1.74, 95% confidence interval (CI) = 1.23-2.46], but not with major bleeding (SHR = 1.24, 95% CI = 0.83-1.86).

CONCLUSION

In elderly patients who receive anticoagulants because of VTE, a high risk of falls is significantly associated with clinically relevant nonmajor bleeding, but not with major bleeding. Whether or not a high risk of falls is a reason against providing anticoagulation beyond 3 months should be based on patient preferences and the risk of VTE recurrence.

The adherence to initial processes of care in elderly patients with acute venous thromboembolism

BACKGROUND

We aimed to assess whether elderly patients with acute venous thromboembolism (VTE) receive recommended initial processes of care and to identify predictors of process adherence.

METHODS

We prospectively studied in- and outpatients aged ≥65 years with acute symptomatic VTE in a multicenter cohort study from nine Swiss university- and non-university hospitals between September 2009 and March 2011. We systematically assessed whether initial processes of care, which are recommended by the 2008 American College of Chest Physicians guidelines, were performed in each patient. We used multivariable logistic models to identify patient factors independently associated with process adherence.

RESULTS

Our cohort comprised 950 patients (mean age 76 years). Of these, 86% (645/750) received parenteral anticoagulation for ≥5 days, 54% (405/750) had oral anticoagulation started on the first treatment day, and 37% (274/750) had an international normalized ratio (INR) ≥2 for ≥24 hours before parenteral anticoagulation was discontinued. Overall, 35% (53/153) of patients with cancer received low-molecular-weight heparin monotherapy and 72% (304/423) of patients with symptomatic deep vein thrombosis were prescribed compression stockings. In multivariate analyses, symptomatic pulmonary embolism, hospital-acquired VTE, and concomitant antiplatelet therapy were associated with a significantly lower anticoagulation-related process adherence.

CONCLUSIONS

Adherence to several recommended processes of care was suboptimal in elderly patients with VTE. Quality of care interventions should particularly focus on processes with low adherence, such as the prescription of continued low-molecular-weight heparin therapy in patients with cancer and the achievement of an INR ≥2 for ≥24 hours before parenteral anticoagulants are stopped.

The Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+): rationale and methodology

Venous thromboembolism (VTE) is common and has a high impact on morbidity, mortality, and costs of care. Although most of the patients with VTE are aged ≥65 years, there is little data about the medical outcomes in the elderly with VTE. The Swiss Cohort of Elderly Patients with VTE (SWITCO65+) is a prospective multicenter cohort study of in- and outpatients aged ≥65 years with acute VTE from all five Swiss university and four high-volume non-university hospitals. The goal is to examine which clinical and biological factors and processes of care drive short- and long-term medical outcomes, health-related quality of life, and medical resource utilization in elderly patients with acute VTE. The cohort also includes a large biobank with biological material from each participant. From September 2009 to March 2012, 1,863 elderly patients with VTE were screened and 1003 (53.8%) were enrolled in the cohort. Overall, 51.7% of patients were aged ≥75 years and 52.7% were men. By October 16, 2012, after an average follow-up time of 512 days, 799 (79.7%) patients were still actively participating. SWITCO65+ is a unique opportunity to study short- and long-term outcomes in elderly patients with VTE. The Steering Committee encourages national and international collaborative research projects related to SWITCO65+, including sharing anonymized data and biological samples.

Glucose control during a driving training in patients with type 1 and type 2 diabetes mellitus - a randomised, controlled trial

AIM

To investigate the effect of prolonged acute mental stress by means of a driving training on glucose control in patients with type 1 and type 2 diabetes mellitus.

METHODS

39 patients with insulin-treated diabetes (18 type 1, 21 type 2 diabetes) were exposed to mental stress by means of a 2 h-driving training. The training session started 15 min after intake of a standard meal. Blood glucose, blood pressure, heart rate, salivary cortisol, and subjective stress perception were monitored in regular intervals and compared to a control day.

RESULTS

On the stress testing day, blood pressure rose from 142/86±16/9 mmHg to 162/95±22/11 mmHg (p<0.001), heart rate from 72±11 bpm to 86±16 bpm (p<0.001) and subjective stress perception from 1.4±0.6 to 4.7±2.5 points (p<0.001). Salivary cortisol concentrations increased from a median of 5.1 nmol/l (Interquartile Range (IQR) 3.5-7.5 nmol/l) at baseline to 7.7 nmol/l (IQR 4.7-12.8 nmol/l, p<0.001), all these measurements remained stable on the control day. Glucose control showed no significant difference on the stress testing day compared to the control day (mean difference over time=0.22 mmol/l, 95%-CI -1.5 to +1.9 mmol/l, p=0.794). A multivariate linear regression and correlation analysis showed no association of demographic characteristics (diabetes type, age, body mass index (BMI), diabetes duration, HbA1c), objective or subjective stress parameters with the course of glucose concentrations during the driving training.

CONCLUSIONS

Although a 2 h-driving training causes increased subjective and objective stress parameters, glucose control is maintained in patients with insulin-treated diabetes.

Prospective, multicenter validation of prediction scores for major bleeding in elderly patients with venous thromboembolism

BACKGROUND

The Outpatient Bleeding Risk Index (OBRI) and the Kuijer, RIETE and Kearon scores are clinical prognostic scores for bleeding in patients receiving oral anticoagulants for venous thromboembolism (VTE). We prospectively compared the performance of these scores in elderly patients with VTE.

METHODS

In a prospective multicenter Swiss cohort study, we studied 663 patients aged ≥ 65 years with acute VTE. The outcome was a first major bleeding at 90 days. We classified patients into three categories of bleeding risk (low, intermediate and high) according to each score and dichotomized patients as high vs. low or intermediate risk. We calculated the area under the receiver-operating characteristic (ROC) curve, positive predictive values and likelihood ratios for each score.

RESULTS

Overall, 28 out of 663 patients (4.2%, 95% confidence interval [CI] 2.8-6.0%) had a first major bleeding within 90 days. According to different scores, the rate of major bleeding varied from 1.9% to 2.1% in low-risk, from 4.2% to 5.0% in intermediate-risk and from 3.1% to 6.6% in high-risk patients. The discriminative power of the scores was poor to moderate, with areas under the ROC curve ranging from 0.49 to 0.60 (P = 0.21). The positive predictive values and positive likelihood ratios were low and varied from 3.1% to 6.6% and from 0.72 to 1.59, respectively.

CONCLUSION

In elderly patients with VTE, existing bleeding risk scores do not have sufficient accuracy and power to discriminate between patients with VTE who are at a high risk of short-term major bleeding and those who are not.

Prospective comparison of clinical prognostic scores in elder patients with a pulmonary embolism

BACKGROUND

The Geneva Prognostic Score (GPS), the Pulmonary Embolism Severity Index (PESI) and its simplified version (sPESI) are well-known clinical prognostic scores for a pulmonary embolism (PE).

OBJECTIVES

To compare the prognostic performance of these scores in elderly patients with a PE.

PATIENTS AND METHODS

In a multicenter Swiss cohort of elderly patients with venous thromboembolism, we prospectively studied 449 patients aged ≥ 65 years with a symptomatic PE. The outcome was 30-day overall mortality. We dichotomized patients as low vs. higher risk in all three scores using the following thresholds: GPS scores ≤ 2 vs. > 2, PESI risk classes I-II vs. III-V and sPESI scores 0 vs. ≥ 1. We compared 30-day mortality in low- vs. higher-risk patients and the areas under the receiver-operating characteristic curve (ROC).

RESULTS

Overall, 3.8% of patients (17/449) died within 30 days. The GPS classified a greater proportion of patients as low risk (92% [413/449]) than the PESI (36.3% [163/449]) and the sPESI (39.6% [178/449]) (P < 0.001 for each comparison). Low-risk patients based on the sPESI had a mortality of 0% (95% confidence interval [CI] 0-2.1%) compared with 0.6% (95% CI 0-3.4%) for low-risk patients based on the PESI and 3.4% (95% CI 1.9-5.6%) for low-risk patients based on the GPS. The areas under the ROC curves were 0.77 (95% CI 0.72-0.81), 0.76 (95% CI 0.72-0.80) and 0.71 (95% CI 0.66-0.75), respectively (P = 0.47).

CONCLUSIONS

In this cohort of elderly patients with PE, the GPS identified a higher proportion of patients as low risk but the PESI and sPESI were more accurate in predicting mortality.

Spezielle Aspekte der Beckenvenenthrombose

Die Beckenvenen sind nur in rund 20 % aller tiefen Venenthrombosen mitbetroffen. Die „normale“ Thrombose bildet sich distal, ist sogenannt aszendierend. Im Gesamtkollektiv der Venenthrombosen findet sich eine leichte Linksbetonung, bei Mitbefall des Beckens ist aber die linke Seite mit einem Faktor 2–3 häufiger involviert. In der Schwangerschaft ist die linke Seite rund 4-mal häufiger als die rechte Seite am Thromboseprozess beteiligt. Auffällig ist auch, dass sich in der Schwangerschaft die proximale Beteiligung von iliakal bis zur Vena femoralis communis in rund 60 % der Fälle nachweisen lässt, also bedeutend häufiger als bei den nicht-schwangeren Individuen. Isolierte Beckenvenenthrombosen sind eine Rarität, die Inzidenz ist unter 1 %. Auch der Befall der Vena ovarica und der Vena iliaca in-terna ist sehr selten, allerdings können beide Venen auch Quellen von Lungenembolien sein.

Der isolierte Befall der Beckenvenen kann ein diagnostisches Problem darstellen. Die Duplexsonographie hat für die Diagnose der isolierten Beckenvenenthrombose eine ungenügende Sensitivität und Spezifität. Die MR-oder CT-Angiographie sind präziser und können diagnostische Alternativen darstellen. Für die Ausprägung der Venenthrombose- und damit auch für die klinischen Verdachtsmomente- ist der Befall des Venensterns resp. der V. femoralis communis sehr wichtig. Ein thrombotischer Verschluss der Mündung der Vena saphena magna bewirkt sowohl bei der aszendierenden als auch bei der deszendierenden Thrombose eine deutliche Verstärkung der klinischen Symptomatik. Sind nur die Becken -segmente proximal der V. femoralis communis betroffen, kann die Klinik sehr diskret sein und damit die Diagnostik erschwert. Venenthrombosen mit Einbezug der Vena femoralis com-munis und der Beckenvenen haben einen deutlich schlechteren Langzeitverlauf bezüglich Entwicklung eines postthrombotischen Syndromes. Aber auch kurzfristige Verlaufs-parameter wie Blutung und Tod sind bei pro-ximaler Mitbeteiligung des Thrombose-Prozesses klar schlechter.

Standardtherapie der Thrombose, auch der Beckenvenenthrombose, ist nach wie vor die Antikoagulation. In ausgewählten Fällen, ins-besondere bei jungen und aktiven Patienten mit einem ausgeprägten Krankheitsbild, können die neueren kombinierten Therapieverfahren wie Thrombektomie, Lyse und Stenteinlage bei Fehlen von Kontraindikationen erwogen werden. Die Bücher dazu sind allerdings offen, die Kontroversen andauernd und nach wie vor besteht für die aktiven invasiven Verfahren bei Thrombosen höchstens ein Evidenzgrad 2.

Predictors of in-hospital mortality in elderly patients with acute venous thrombo-embolism: the SWIss Venous ThromboEmbolism Registry (SWIVTER)

AIMS

Although acute venous thrombo-embolism (VTE) often afflicts patients with advanced age, the predictors of in-hospital mortality for elderly VTE patients are unknown.

METHODS AND RESULTS

Among 1247 consecutive patients with acute VTE from the prospective SWIss Venous ThromboEmbolism Registry (SWIVTER), 644 (52%) were elderly (≥65 years of age). In comparison to younger patients, the elderly more often had pulmonary embolism (PE) (60 vs. 42%; P< 0.001), cancer (30 vs. 20%; P< 0.001), chronic lung disease (14 vs. 8%; P= 0.001), and congestive heart failure (12 vs. 2%; P< 0.001). Elderly VTE patients were more often hospitalized (75 vs. 52%; P< 0.001), and there was no difference in the use of thrombolysis, catheter intervention, or surgical embolectomy between the elderly and younger PE patients (5 vs. 6%; P= 0.54), despite a trend towards a higher rate of massive PE in the elderly (8 vs. 4%; P= 0.07). The overall in-hospital mortality rate was 6.6% in the elderly vs. 3.2% in the younger VTE patients (P= 0.033). Cancer was associated with in-hospital death both in the elderly [hazard ratio (HR) 4.91, 95% confidence interval (CI) 2.32-10.38; P< 0.001] and in the younger patients (HR 4.90, 95% CI 1.37-17.59; P= 0.015); massive PE was a predictor of in-hospital death in the elderly only (HR 3.77, 95% CI 1.63-8.74; P= 0.002).

CONCLUSION

Elderly patients had more serious VTE than younger patients, and massive PE was particularly life-threatening in the elderly.

[Severe methemoglobinaemia following sodium nitrite ingestion]

We report the case of a patient suffering from a severe methemoglobinaemia following accidental sodium nitrite intoxication, a substance frequently used as a preservation agent for animal feed. On base of this case report, pathophysiology, clinical symptoms, diagnostical and therapeutical options with methylene blue (1-2 mg/kg of body weight) are discussed. Recently, pulse oximeters capable to measure 4 different hemoglobins have been introduced. These may be helpful for diagnosis especially in the prehospital setting.

Intima-media thickness and carotid resistive index: progression over 6 years and predictive value for cardiovascular events

PURPOSE

Intima-media thickness (IMT) of the common carotid artery and the resistive index (RI) of the internal carotid artery correlate with the degree of atherosclerosis and are predictors of cardiovascular morbidity and mortality. Limited or no data are available about long-term predictive values and the progression of the two markers themselves.

MATERIALS AND METHODS

145 patients with at least one cardiovascular risk factor or clinically manifest atherosclerosis were included. At enrollment and after 36 and 74 months, duplex sonographic measurements of IMT CCA and RI ICA were performed. During follow-up, the occurrence of cardiovascular events (cardiovascular death, myocardial infarction, stroke) was assessed.

RESULTS

At baseline, IMT was 0.79 +/- 0.16 mm and RI 0.66 +/- 0.08. Log-rank analysis showed a continuous increase in the risk of a cardiovascular event with an increasing range of IMT (p = 0.011) and RI (p = 0.006). IMT progression in patients with low versus high atherosclerotic burden (as defined by SMART score < or =7 points and > 7 points) differs significantly (32 +/- 83 microm versus 95 +/- 125 microm; p < 0.002). IMT progression was even more pronounced in patients suffering a cardiovascular event (141 +/- 105 microm versus 54 +/- 111 microm; p < 0.001). No significant RI ICA progression could be detected during follow-up in any group (patients with low vs. high atherosclerotic burden 0.00 +/- 0.06 versus 0.00 +/- 0.04; p = n. s.; patients with vs. without cardiovascular event 0.00 +/- 0.05 versus 0.01 +/- 0.03; p = n. s.).

CONCLUSION

Our results confirm the predictive value for cardiovascular events of RI and IMT in long-term follow-up. In contrast to RI, IMT increases over six years, above all in patients suffering a cardiovascular event. The results suggest that IMT is suitable for cardiovascular risk prediction as well as for progression measurements, while RI cannot be recommended for progression measurements. The effect of drug therapy on RI needs further clarification.

Clinical predictors of prophylaxis use prior to the onset of acute venous thromboembolism in hospitalized patients SWIss Venous ThromboEmbolism Registry (SWIVTER)

BACKGROUND

We investigated clinical predictors of appropriate prophylaxis prior to the onset of venous thromboembolism (VTE).

METHODS

In 14 Swiss hospitals, 567 consecutive patients (306 medical, 261 surgical) with acute VTE and hospitalization < 30 days prior to the VTE event were enrolled.

RESULTS

Prophylaxis was used in 329 (58%) patients within 30 days prior to the VTE event. Among the medical patients, 146 (48%) received prophylaxis, and among the surgical patients, 183 (70%) received prophylaxis (P < 0.001). The indication for prophylaxis was present in 262 (86%) medical patients and in 217 (83%) surgical patients. Among the patients with an indication for prophylaxis, 135 (52%) of the medical patients and 165 (76%) of the surgical patients received prophylaxis (P < 0.001). Admission to the intensive care unit [odds ratio (OR) 3.28, 95% confidence interval (CI) 1.94-5.57], recent surgery (OR 2.28, 95% CI 1.51-3.44), bed rest > 3 days (OR 2.12, 95% CI 1.45-3.09), obesity (OR 2.01, 95% CI 1.03-3.90), prior deep vein thrombosis (OR 1.71, 95% CI 1.31-2.24) and prior pulmonary embolism (OR 1.54, 95% CI 1.05-2.26) were independent predictors of prophylaxis. In contrast, cancer (OR 1.06, 95% CI 0.89-1.25), age (OR 0.99, 95% CI 0.98-1.01), acute heart failure (OR 1.13, 95% CI 0.79-1.63) and acute respiratory failure (OR 1.19, 95% CI 0.89-1.59) were not predictive of prophylaxis.

CONCLUSIONS

Although an indication for prophylaxis was present in most patients who suffered acute VTE, almost half did not receive any form of prophylaxis. Future efforts should focus on the improvement of prophylaxis for hospitalized patients, particularly in patients with cancer, acute heart or respiratory failure, and in the elderly.

Quantitative d-dimer levels and the extent of venous thromboembolism in CT angiography and lower limb ultrasonography

BACKGROUND

We evaluated the diagnostic yield of multidetector-row CT angiography and determined the clot burden within pulmonary vasculature as a measure of pulmonary embolism (PE) severity at different d-dimer levels and pretest clinical probabilities.

PATIENTS AND METHODS

254 consecutive patients referred to CT pulmonary angiography for suspected PE after d-dimer testing were grouped into clinical probability classes using Wells' score, and the frequency of PE was determined. A score representing clot burden within pulmonary vasculature was calculated from the number of obstructed segmental arteries in CT scans in a partly differing group of 96 PE positive patients.

RESULTS

The prevalence of PE increases with the d-dimer level (7% at d-dimer levels of 0.5-1 microg/ml, reaching 90% at d-dimer levels > 9 microg/ml; p < 0.001). D-dimer levels above 4 microg/ml are associated with a significantly higher clot burden in pulmonary arteries (median score 11 versus 5, and 53% versus 16% of patients in the subgroup with a score > 10 points; p < 0.001), and thrombus in a main pulmonary artery was detected more frequently (37% versus 9%, p = 0.003). Similar results were obtained for distal versus proximal deep venous thromboses, detected by ultrasonography of the lower limb in a separate group of 44 patients.

CONCLUSIONS

High d-dimer levels are associated with an increased prevalence of CT radiographic findings indicating extended clinically severe PE or lower limb venous thrombosis.

Prediction of cardiovascular morbidity and mortality: comparison of the internal carotid artery resistive index with the common carotid artery intima-media thickness

BACKGROUND AND PURPOSE

The intima-media thickness (IMT) of the common carotid artery (CCA) is well correlated with the degree of arteriosclerosis and is a predictor of cardiovascular morbidity and mortality. The (hemodynamic) resistive index (RI) of the internal carotid artery (ICA) correlates with the degree of arteriosclerosis just as well as IMT. The aim of the study was to compare the predictive values of RI and IMT with regard to cardiovascular morbidity and mortality.

METHODS

A total of 146 patients with cardiovascular risk factors or established arteriosclerosis were included. Duplex sonography of the CCA and ICA was performed, and the IMT and RI were measured in both vessels. During follow-up for a median of 36 months, the occurrence of cardiovascular events (myocardial infarction, stroke, or cardiovascular death) was assessed.

RESULTS

Thirty-nine cardiovascular events occurred in 28 patients (19.2%). The relative risk for a cardiovascular event per increase of the IMT by 1 SD (0.16 mm) was 1.53 (95% CI, 1.07 to 2.18) and 1.91 (95% CI, 1.34 to 2.73) for RI ICA (0.08). The event rate in patients with IMT <0.79 mm (mean) and RI ICA <0.66 (mean) was 11.8% and 12.7% compared with 25.6% (P=0.03) and 25.0% (P=0.06) in patients with IMT > or =0.79 mm and RI ICA > or =0.66, respectively. Log rank analysis showed a continuous increase in the risk of cardiovascular event with increasing range of the IMT (P=0.029) and RI ICA (P<0.001).

CONCLUSIONS

The RI ICA is a predictor of cardiovascular mortality and morbidity, at least comparable to the well-established IMT.

[Morphological and hemodynamic indicators of early arteriosclerosis]

Das früheste, noch funktionelle Stadium der Arteriosklerose, die endotheliale Dysfunktion, kann mittels ultraschallbasierter Messung der Vasoreaktivität an der A. brachialis zuverlässig erfasst werden. Sowohl die Intima-Media-Dicke (IMT) als sonomorphologischer Parameter, als auch der dopplerbasierte Widerstandsindex RI, sind zuverlässige Indikatoren der Arteriosklerose. Eine scharfe Abgrenzung zwischen reversiblen Frühstadien und nicht reversiblen Spätstadien ist für beide Parameter zum jetzigen Zeitpunkt aber nicht etabliert. IMT-Werte über 0,8mm und RI-Werte über 0,72 scheinen aber eine ausgedehnte und wahrscheinlich nicht mehr zum normalen Gefäss reversible Arteriosklerose zu repräsentieren. Die prognostische Bedeutung eines pathologischen Intima-Media-Komplexes bezüglich kardiovaskulärer Morbidität und Mortalität ist etabliert, jene für den Widerstandsindex offen und durch weitere Studien zu belegen.

[Conservative treatment of acute embolisms of the carotid bifurcation]

Embolic events of the carotid bifurcatin are a rare cause of cerebrovascular accidents. We observed two patients who showed a spontaneous recanalisation of an embolic occlusion of the extracranial vessels when treated with conservative procedure using heparin. Both patients had a near complete remission of the symptoms without impairment in their daily activities.

Comparison of carotid arterial resistive indices with intima-media thickness as sonographic markers of atherosclerosis

Background and Purpose-The intima-media thickness (IMT) of the carotid artery is a (morphological) sonographic parameter that depends on the degree of atherosclerosis. In the renal arteries, the value of the (hemodynamic) resistive index (RI) is correlated with the severity of atherosclerosis. In contrast to the well-known IMT, no study has yet applied the carotid RI to estimate generalized atherosclerosis.

METHODS

-The SMART atherosclerosis risk score was determined in 157 patients (94 men and 63 women; mean age 63 [range 19 to 80] years) with at least 1 vascular risk factor or a known vascular disease. Duplex sonography of the common carotid (CCA) and internal carotid artery (ICA) was then performed, with determination of IMT and RI.

RESULTS

-The mean risk score of all patients was 8.8+/-3.5 (range 1 to 17), the mean IMT value in the CCA was 0.727+/-0.161 mm, the mean RI in CCA was 0.79+/-0.066, and the mean RI in ICA was 0.661+/-0.082. Highly significant correlations were found between the score and IMT CCA and the score and RI ICA (r=0.62, P:<0.0001 and r=0.55, P:<0.0001). The score-RI CCA correlation was much less marked (r=0.354, P:<0.0001). The intraobserver and interobserver agreement was less for IMT than for RI CCA and ICA. The areas under the curve of the receiver operating curves to distinguish between low-risk and high-risk patients resulted in values of 0.86, 0.81, and 0.69 for IMT, RI ICA, and RI CCA, respectively.

CONCLUSIONS

-Although RI reflects the atherosclerotic process in an indirect manner, the correlation between the RI ICA and the SMART atherosclerosis score as well as the ability to distinguish between low- and high-risk patients are comparable to those of the well-known IMT.

[Tick-borne meningoencephalitis in Thurgau Canton: a clinical and epidiomological analysis]

BACKGROUND

Tick-borne meningo-encephalitis (TBE) is caused by a flavivirus species that is transmitted from rodents to humans by Ixodes ticks. The clinical picture of central nervous system involvement varies from febrile headache to lethal encephalitis. To date no specific treatment exists, although protective active immunisation is available.

METHODS

We present the clinical and epidemiological data from 73 patients with TBE who acquired the infection in Canton Thurgau in the years 1996-1999.

RESULTS

Canton Thurgau is a state in eastern Switzerland with a population of 230,000. Within the last five years the reported cases of TBE have increased more than threefold. The area where infectious tick bites were registered has expanded from the western to the eastern part and now encompasses the entire state. The risk of infection is clearly related to frequent activities in wooded areas, though outdoor activities not in forests also carry a considerable risk. In > 80% of the cases a postviral neurasthenic syndrome develops involving absence from work for two months on average. In the elderly and patients who present with encephalitic symptoms, a worse outcome with persistent neurological symptoms or even death has been observed.

CONCLUSION

The increasing incidence of TBE, the expansion of infectious ticks to the east and high morbidity justify active immunisation against TBE on a broad scale in Canton Thurgau.

Optimising the use of carotid duplex sonography

AIM

We analysed factors influencing diagnostic yield and treatment and their potential for optimising the use of carotid duplex sonography (CDS).

METHOD

Patients referred for CDS were divided into three groups: 1: high likelihood of carotid symptoms, 2: suspected presence of asymptomatic carotid lesions, 3: other indications. Clinical data, the grading of stenosis and the therapeutic consequences were analysed. The efficiency of diagnosis was tested with an algorithm.

RESULTS

344 patients were included. Groups 1, 2 and 3 contained > or = 1 pathological finding in the carotid or vertebral system in 68%, 86% and 55% respectively, whereas high-grade stenoses or occlusions of the internal carotid artery (ICA) were detected in 10.8%, 16% and 3.6% respectively. Age > 50, > 1 risk factor, carotid murmur and concomitant vascular disease were associated with a significantly higher diagnostic yield. Subsequent treatment in groups 1, 2 and 3 involved carotid thromboendarterectomy in 6.4%, 2% and 0.7% respectively and the start of treatment with a platelet aggregation inhibitor in 9%, 30% and 17% respectively. The optimisation algorithm would have saved 21% of CDS scans.

CONCLUSION

Clinical pre-selection criteria determine the diagnostic yield of CDS. The potential for optimisation depends on the treatment regimen chosen for asymptomatic stenoses and secondary prophylaxis.

Duplex sonographic registration of age and diabetes-related loss of renal vasodilatory response to nitroglycerine

BACKGROUND

Nitroglycerine effects dilatation of the vas afferens in the kidney by its active metabolite nitric oxide (NO). In diabetic nephropathy, NO appears to cause hyperfiltration and proteinuria. The aim of this study was to investigate the potential of duplex Doppler ultrasonography in recording changes in resistive indices following nitroglycerine and whether the extent of changes in diabetic nephropathy is reduced as a result of the arteriolar dilatation mediated by NO.

METHODS

Fifty-three subjects made up three groups: group 1, 12 young healthy volunteers (5 male, 7 female, 28+/-6 years); group 2, 21 older healthy volunteers (7 male, 14 female, 62+/-8 years); group 3, 20 patients (13 male, 7 female, 56+/-18 years) with mild diabetic nephropathy. The resistive index (RI) was measured in the interlobar arteries before, and 1, 3 and 5 min after administration of 0.8 mg sublingual nitroglycerine.

RESULTS

The initial RI of 0.592 decreased in group 1 by 10.8% (P<0. 01) after nitroglycerine, in group 2 the initial figure of 0.631 decreased by 5.9% (P<0.01), and in group 3 the initial figure of 0. 669 decreased by 3.4% (P<0.01). Initial RI values differed significantly between groups 1 and 3 (P<0.01) and groups 1 and 2 (P<0.01), as did values between all healthy volunteers (groups 1 and 2, n=33) and patients with nephropathy (P<0.005). The extent of DeltaRI differed significantly between groups 1 and 3 (P<0.01), 1 and 2 (P<0.02), and between all volunteers and group 3 (P<0.003). In groups 1 and 2 the initial RI was dependent on age (P<0.03), in group 3 on age and creatinine clearance (P<0.02 and P<0.05 respectively). DeltaRI correlated with age in the healthy subjects (P<0.01) and with duration of diabetes in diabetic nephropathy (P0. 03).

CONCLUSIONS

Haemodynamic changes in renal perfusion caused by nitroglycerine can be detected using duplex ultrasonography. In healthy subjects, DeltaRI declines with increasing age. In diabetic nephropathy patients, the response to nitroglycerine is reduced. The increased initial RI in such patients suggests fixed arteriolar damage.

Assessment of collateral perfusion: a pharmacodynamic study with buflomedil hydrochloride

The aim of the study was to assess the influence of Buflomedil hydrochloride on collateral function. Ten patients with isolated superficial femoral occlusions were investigated twice by duplex sonography with measurement sites at the common femoral artery (CF) and the popliteal artery (PA). After the second scan 200 mg of Buflomedil hydrochloride were infused; the infusion was followed by a third duplex examination. Endpoints assessed included the arterial diameter (D(CF), D(PA)), the systolic peak velocity (Vmax), the mean velocity of the maximum envelope (Vmean m.e.), the intensity weighted time average mean velocity (Vmean i.w.), the maximum reverse flow velocity (Vrev), the end-diastolic velocity (Venddiast), the calculated volume flow (Q), the pulsatility and the resistance indices (PI, RI), and PI and RI based segmental damping factors (DF(PI), DF(RI)). For the CF measurement site the infusion of Buflomedil hydrochloride resulted in a significant reduction in Vrev and PI (p<0.05), whereas trends in the opposite direction (increase) were observed for both measures of Vmean and for Q (0.1<p<0.05). No significant changes were reported for the PA measurement site. DF(PI) numerically decreased (0.1<p<0.05). The pattern of changes suggest that Buflomedil hydrochloride induces collateral vasodilation and thus improves collateral function.

[Headache, general malaise and left-side ptosis]

A 82-year-old female was admitted to hospital because of deteriorated general condition, severe diffuse headache and complete left-sided ptosis. A computed tomography scan of the head revealed no subarachnoid haemorrhage. Based on the hypothesis that the symptoms resulted from an infarction in the brain stem, the previous medication with Aspirin was continued. After repeated vomitus hypotensive dehydration developed and was adequately treated. Because of confusion, elevated white blood counts and signs of meningism, a spinal puncture was performed. Only the serology for Borrelia-IgG was positive, therefore the patient received Rocephin. During treatment only the ptosis persisted, therefore the substitution with sodium and the medication with Prednisone were stopped. Afterwards the symptoms reappeared and the laboratory results showed insufficiency of the pituitary. A magnetic resonance scan showed a microadenoma of the pituitary with local bleeding. Nine months after pituitary apoplexy, with hormonal substitution only a divergent strabism on the left side persisted. Clinical findings, course and therapy of pituitary apoplexy are discussed.

[Therapy-resistant lumbago]

The 71-year-old female patient was hospitalized owing to a therapy-resistant lumbo-spondylogenic syndrome. Radiology with increased infection parameters gave rise to the suspicion of a bacterial spondylodiscitis L1/L2. Puncture of the vertebral body as well as blood cultures established proof of yersinia enterocolitica. In spite of immediate adequate antibiosis, by means of "Ciprofloxacin" i.v. spondylodesis of the lumbar spine had to be carried out in order meet the threat of instability. Spondylodiscitis is an extremely rare manifestation of a yersinia infection, only few cases have been described so far in medical literature.

[Development of early-summer meningoencephalitis (FSME) in the Thurgau region 1990-1995--a new endemic area?]

Tick-borne encephalitis (TBE) is a viral infection transmitted by bites of infected ticks. The clinical course is mostly mild, but death occurs in 1-2% of TBE infections and nearly half of patients with meningitis/meningoencephalitis show residual disease, above all chronic headache. TBE-infected ticks occur only in endemic areas. A knowledge of the endemic areas is very important for immunoprophylaxis of TBE. In recent years between 26 and 97 cases of TBE have occurred in Switzerland. The largest endemic areas are in Canton Schaffhausen, the northern part of Canton Zurich and the north-west of Canton Thurgau. Another endemic area is known in the region of Thun in Canton Berne. Another possible endemic area is known in the Zurich Oberland around Elgg, only 7 km from Aadorf in Thurgau. Up to now, Diessenhofen in the north-west of Thurgau was the only known possible endemic area. In 1994 and 1995 we observed an accumulation of TBE infections in western Thurgau. The question was whether there are other endemic areas in Thurgau. In this retrospective analysis we studied the TBE cases in Thurgau between 1990 and 1995 with data derived from the cantonal health authorities reports. Clinical data were taken from case histories of the two cantonal hospitals in Frauenfeld and Münsterlingen, completed by data from family doctors and patients. Between 1990 and 1995 30 TBE infections (1990; 1, 1991: 4, 1992: 3, 1993: 1, 1994: 4 certain, 3 uncertain, 1995: 14) were observed. TBE infections appeared between May and October (maximum in May). 14 patients remembered a bite by a tick several weeks before onset of the illness. 7 bites occurred in the area of Frauenfeld/Aadorf. Only one bite occurred in Diessenhofen. 2 patients were infected in well-known endemic areas in Canton Zurich, a vicinal region in the west of Thurgau. In 1995 the incidence of TBE in Thurgau was 5.4/100000 population. In 9 of the 14 patients recalling a bite by a tick (64.4%), the bites occurred near their domicile. No bite was seen east of a line between Steckborn and Weinfelden. The incidence of TBE in Thurgau in 1995 was clearly higher than the average in Switzerland in recent years (0.46/100000), and higher than in the well-known endemic areas in the vicinity (Schaffhausen 3.95, Zurich 1.31). Based on our data, the region Frauenfeld/Aadorf must be declared a new endemic area for TBE. Probably the well-known endemic area in the Zurich Oberland in the vicinity of Elgg has spread eastward. Persons who are often in the forests of this region should be advised to be vaccinated.