Adherence to cardiac rehabilitation after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially cardiac rehabilitation proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and overall modification of cardiovascular risk factors. However, profound epidemiological measures on adherence to a recommended cardiac rehabilitation after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to cardiac rehabilitation after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to recommended cardiac rehabilitation was investigated according to health insurance documentation. Patients were followed prospectively until the primary study endpoint (= mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to cardiac rehabilitation on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 16.518 patients (median age: 64 years [54–74]; male: 68.4% [n=11.306]) met the inclusion criteria. Of alarming importance 86.6% (n=14.305) of all patients presenting with ACS did not perform any cardiac rehabilitation as recommended by current guidelines. During patient follow-up until 01/2018 a total of 1774 (10.7%) individuals died. Adherence to recommended cardiac rehabilitation had a strong an independent inverse association with mortality with an adjusted hazard ratio of 0.73 (95% CI: 0.54–0.98; p=0.036) (see Figure 1).

Conclusion

The present nationwide investigation highlighted an overall low adherence to recommended cardiac rehabilitation after ACS. Since cardiac rehabilitation after ACS was associated with a 27% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of cardiac rehabilitation and associated intensified risk factor modification should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative mortality

Funding Acknowledgement

Type of funding source: None

Adherence to high-intensity statin therapy after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially lipid lowering therapy – via high-intensity statins (atorvastatin and rosuvastatin) – proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and stent thrombosis. However, profound epidemiological measures on adherence to statin intake after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to high-intensity statin therapy after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to high-intensity statins was investigated according to handing in prescriptions for rosuvastatin and atorvastatin at local pharmacies. Patients were followed prospectively until the primary study endpoint (=mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to high-intensity statin therapy on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 23.240 patients (median age: 65 years [55–75]; male: 67.7% [n=15.728]) met the inclusion criteria. Individuals that died during the index event (n=366; 1.6%), presented with a re-ACS (n=569; 2.4%) or were lost during follow-up (n=158; 0.6%) were not included within the final analysis. Of alarming importance 66.4% (n=15.422) of all patients presenting with ACS did not take high-intensity statins as recommended by current guidelines. The highest rate of drug interruption/end of therapy was observed within the first month after the index event with more than 50% of all cases. During patient follow-up until 01/2018 a total of 3522 (15.2%) individuals died. Non-adherence to high-intensity statins had a strong an independent association with mortality with an adjusted hazard ratio of 1.16 (95% CI: 1.06–1.25; p<0.001) (see Figure 1).

Conclusion

The present nationwide investigation highlighted an overall low adherence to high-intensity statins after ACS, with the highest interruption/end of therapy rate within the first month after the index event. Since the intake of high-intensity statins after ACS was associated with a 14% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of drug-adherence and intensified patient follow-up should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative mortality

Funding Acknowledgement

Type of funding source: None

Adherence to dual anti-platelet therapy after acute coronary syndrome and its impact on patient outcome

Background

Secondary prevention after acute coronary syndrome (ACS) mirrors a key position in the reduction of morbidity and mortality in this highly vulnerable patient population. Especially dual anti-platelet therapy (DAPT) – including aspirin plus a P2Y12 inhibitor – proved to be one of the most beneficial therapeutic approaches for the reduction of re-events and stent thrombosis. However, profound epidemiological measures on adherence to DAPT intake after ACS remain scare, but seem of major importance in terms of preventing fatal cardiac adverse events. Therefore, we aimed to investigate adherence to DAPT after ACS and its impact on patient outcome from an Austrian nationwide perspective.

Methods

Within this population-based national observation all patients presenting with ACS between 04/2011 and 8/2015 in Austria were enrolled. Patient characteristics and co-morbidities were assessed via the Austrian national health insurance system and elucidated according to ICD10 definitions. Adherence to DAPT was investigated according to handing in prescriptions for aspirin and P2Y12 inhibitors at local pharmacies. Patients were followed prospectively until the primary study endpoint (=mortality) was reached. Cox Regression hazard analysis was used to investigate the impact of non-adherence to DAPT on patient outcome and was adjusted for a comprehensive subset of confounders within the multivariate model.

Results

During the observation period a total of 22.331 patients (median age: 65 years [55–75]; male: 69.7% [n=15.176]) met the inclusion criteria. Patients presenting with the indication for oral anticoagulation (n=2165; 9.7%), individuals that died during the index event (n=151; 0.7%), patients that presented with a re-ACS (n=396; 1.7%) or those who were lost during follow-up (n=96; 0.4%) were not included within the final analysis. Of alarming importance 70.7% (n=15.792) of all patients presenting with ACS did not take DAPT as recommended by current guidelines. The highest rate of drug interruption/end of therapy was observed within the first month after the index event with almost 50% of all cases. During patient follow-up until 14 months after the index event 513 individuals died. Non-adherence to DAPT proved a strong an independent association with mortality with an adjusted hazard ratio of 1.25 (95% CI: 1.09–1.41; p<0.001). (see Figure 1)

Conclusion

The present nationwide investigation highlighted an overall low adherence to DAPT after ACS, with the highest interruption/end of therapy rate within the first month after the index event. Since the intake of DAPT after ACS was associated with a 20% risk reduction for fatal cardiovascular events during the observation period, awareness in terms of drug-adherence and intensified patient follow-up should be promoted, in order to prevent fatal atherothrombotic events.

Figure 1. Cumulative Mortality

Funding Acknowledgement

Type of funding source: None

Macrophage migration inhibitory factor and its binding partner HTRA1 are expressed by olfactory ensheathing cells

Macrophage migration inhibitory factor (MIF) is an important regulator of innate immunity with key roles in neural regeneration and responses to pathogens, amongst a multitude of other functions. The expression of MIF and its binding partners has been characterised throughout the nervous system, with one key exception: the primary olfactory nervous system. Here, we showed in young mice (postnatal day 10) that MIF is expressed in the olfactory nerve by olfactory ensheathing glial cells (OECs) and by olfactory nerve fibroblasts. We also examined the expression of potential binding partners for MIF, and found that the serine protease HTRA1, known to be inhibited by MIF, was also expressed at high levels by OECs and olfactory fibroblasts in vivo and in vitro. We also demonstrated that MIF mediated segregation between OECs and J774a.1 cells (a monocyte/macrophage cell line) in co-culture, which suggests that MIF contributes to the fact that macrophages are largely absent from olfactory nerve fascicles. Phagocytosis assays of axonal debris demonstrated that MIF strongly stimulates phagocytosis by OECs, which indicates that MIF may play a role in the response of OECs to the continual turnover of olfactory axons that occurs throughout life.

Olfactory Ensheathing Cells for Spinal Cord Injury: Sniffing Out the Issues

Olfactory ensheathing cells (OECs) are glia reported to sustain the continuous axon extension and successful topographic targeting of the olfactory receptor neurons responsible for the sense of smell (olfaction). Due to this distinctive property, OECs have been trialed in human cell transplant therapies to assist in the repair of central nervous system injuries, particularly those of the spinal cord. Though many studies have reported neurological improvement, the therapy remains inconsistent and requires further improvement. Much of this variability stems from differing olfactory cell populations prior to transplantation into the injury site. While some studies have used purified cells, others have used unpurified transplants. Although both preparations have merits and faults, the latter increases the variability between transplants received by recipients. Without a robust purification procedure in OEC transplantation therapies, the full potential of OECs for spinal cord injury may not be realised.

Enhancing the Therapeutic Potential of Olfactory Ensheathing Cells in Spinal Cord Repair Using Neurotrophins

Autologous olfactory ensheathing cell (OEC) transplantation is a promising therapy for spinal cord injury; however, the efficacy varies between trials in both animals and humans. The main reason for this variability is that the purity and phenotype of the transplanted cells differs between studies. OECs are susceptible to modulation with neurotrophic factors, and thus, neurotrophins can be used to manipulate the transplanted cells into an optimal, consistent phenotype. OEC transplantation can be divided into 3 phases: (1) cell preparation, (2) cell administration, and (3) continuous support to the transplanted cells in situ. The ideal behaviour of OECs differs between these 3 phases; in the cell preparation phase, rapid cell expansion is desirable to decrease the time between damage and transplantation. In the cell administration phase, OEC survival and integration at the injury site, in particular migration into the glial scar, are the most critical factors, along with OEC-mediated phagocytosis of cellular debris. Finally, continuous support needs to be provided to the transplantation site to promote survival of both transplanted cells and endogenous cells within injury site and to promote long-term integration of the transplanted cells and angiogenesis. In this review, we define the 3 phases of OEC transplantation into the injured spinal cord and the optimal cell behaviors required for each phase. Optimising functional outcomes of OEC transplantation can be achieved by modulation of cell behaviours with neurotrophins. We identify the key growth factors that exhibit the strongest potential for optimizing the OEC phenotype required for each phase.

Lenalidomide normalizes tumor vessels in colorectal cancer improving chemotherapy activity

Background

Angiogenesis inhibition is a promising approach for treating metastatic colorectal cancer (mCRC). Recent evidences support the seemingly counterintuitive ability of certain antiangiogenic drugs to promote normalization of residual tumor vessels with important clinical implications. Lenalidomide is an oral drug with immune-modulatory and anti-angiogenic activity against selected hematologic malignancies but as yet little is known regarding its effectiveness for solid tumors. The aim of this study was to determine whether lenalidomide can normalize colorectal cancer neo-vessels in vivo, thus reducing tumor hypoxia and improving the benefit of chemotherapy.

Methods

We set up a tumorgraft model with NOD/SCID mice implanted with a patient-derived colorectal cancer liver metastasis. The mice were treated with oral lenalidomide (50 mg/Kg/day for 28 days), intraperitoneal 5-fluorouracil (5FU) (20 mg/Kg twice weekly for 3 weeks), combination (combo) of lenalidomide and 5FU or irrelevant vehicle. We assessed tumor vessel density (CD146), pericyte coverage (NG2; alphaSMA), in vivo perfusion capability of residual vessels (lectin distribution essay), hypoxic areas (HP2-100 Hypoxyprobe) and antitumor activity in vivo and in vitro.

Results

Treatment with lenalidomide reduced tumor vessel density (p = 0.0001) and enhanced mature pericyte coverage of residual vessels (p = 0.002). Perfusion capability of tumor vessels was enhanced in mice treated with lenalidomide compared to controls (p = 0.004). Accordingly, lenalidomide reduced hypoxic tumor areas (p = 0.002) and enhanced the antitumor activity of 5FU in vivo. The combo treatment delayed tumor growth (p = 0.01) and significantly reduced the Ki67 index (p = 0.0002). Lenalidomide alone did not demonstrate antitumor activity compared to untreated controls in vivo or against 4 different mCRC cell lines in vitro.

Conclusions

We provide the first evidence of tumor vessel normalization and hypoxia reduction induced by lenalidomide in mCRC in vivo. This effect, seemingly counterintuitive for an antiangiogenic compound, translates into indirect antitumor activity thus enhancing the therapeutic index of chemotherapy. Our findings suggest that further research should be carried out on synergism between lenalidomide and conventional therapies for treating solid tumors that might benefit from tumor vasculature normalization.

OC-07 - Decoding risk for thromboembolic events in lymphoma patients

INTRODUCTION

There are few prediction tools for estimating the risk of thrombosis but they are based on studies performed on hospitalized medical patients without cancer or on hospitalized neutropenic cancer patients without special consideration to lymphoma patients.

AIM

Aim of our study was to determine incidence of thromboembolic (TE) events in patients with non Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and chronic lymphocytic leukemia (CLL)/ small lymphocytic lymphoma (SLL) who were hospitalized to the lymphoma department in the Clinic of hematology, Clinical Center Serbia, Belgrade and Clinic of hematology, Clinical Center Kragujevac. Also, we assessed 2 predictive models (Padua and Khorana score) and create new model for the identification of lymphoma patients at risk for thromboembolism.

MATERIALS AND METHODS

We reviewed all medical records of patients with with NHL, HL and CLL/SLL diagnosed and treated at two previously mentioned institution between January 2006 and December 2014.

RESULTS

The study population included 1820 eligible lymphoma patients. Of all the patients included in the study, 99 (5.4%) developed at least one TE during a follow-up period of 3 months from the end of therapy. In the final multivariate analysis, the following variables were independently associated with risk of TE: previous VTE and/or arterial events, reduced mobility (ECOG 2-4), obesity (BMI >30 kg/m(2)), extranodal localization, mediastinum involvement, development of neutropenia during therapy and hemoglobin level less than 100g/L. Subsequently, we assigned points for the risk model based on the regression coefficients obtained from the final model and developed Thrombosis Lymphoma (ThroLy) score consisting of all significant variables from the multivariate analysis. The Throly score was arrived at by assigning 2 points for all parameters with an OR >5 in multivariate regression analyses (e.g., previous VTE and arterial events, mediastinum involvement, and BMI) and 1 point for rest all other significant variables. Finally, population were divided into 3 risk categories for TE based on the score from the risk model: low (score 0-1), intermediate (score 2-3) and high (score >3). High risk score had a positive predictive value (probability of TE in those designated high risk) of 65.2%.

CONCLUSIONS

Significance of our investigation is development of score that help phisicians to recruit lymphoma patients at risk for development of thromboembolic complications. Also, we can say that our score is dynamic allowing us to change approach during different phase of therapy and is not limited to outpatient settings or with some complicated laboratory analysis.

Orbital and ocular adnexal Mucosa-Associated Lymphoid Tissue (MALT) lymphomas: a single-center 10-year experience

Orbital and ocular andexal Mucosa-Associated Lymphoid Tissue Lymphoma (MALT) or ocular adnexal MALT lymphoma (OAML) is the most common of all eye non-Hodgkin lymphomas. Autoimmune inflammatory disorders and chronic infections are important etiological factors and CD5 and CD43 (sialophorin) tumor markers are significant negative prognostic factors. Disease signs and symptoms can occur a long time before diagnosis. Varieties of treatment options are available. The aim of this retrospective analysis was to compare the efficiency of different treatment options and to investigate disease outcome. Twenty OAML patients, diagnosed in the Clinic of Hematology, Clinical Centre of Serbia, between 2003 and 2013, were enrolled. In most cases, OAML developed in the eighth decade with greater incidence in the male population. Median age was 67.5 years. The median period between the appearance of local signs and symptoms and diagnosis was 7 months. The dominant sign at presentation was swelling of involved tissue (40%). The most common was orbital involvement (55%). All patients had localized disease. Observed laboratory parameters on presentation showed low disease activity. Sialophorin prognostic significance was not registered. Our patients were initially treated differently but there was no significant difference in progression-free survival (PFS) due to initial treatment option (p = 0.2957). Median PFS was 22 months (3-89), and 5-year PFS was 60%. Median overall survival (OS) was 43 months (1-105) and 5-year OS 95%. Eight patients (40%) relapsed and one patient died due to non-hematological complications. In our experience, most modern induction treatment options appear to result in the same, favorable outcome.

Xerostomia after radiotherapy. What matters--mean total dose or dose to each parotid gland?

PURPOSE

Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer. We undertook a prospective study of the effect on xerostomia and outcomes of sparing one or both parotid glands during radiotherapy for patients with squamous cell carcinoma of the head and neck.

METHODS AND MATERIALS

Patients with locally advanced squamous cell carcinoma of the head and neck received definitive (70 Gy in 2 Gy fractions) or adjuvant (60-66 Gy in 2 Gy fractions) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate. Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid.

RESULTS

The study included 126 patients; 114 (55 in group A and 59 in group B) had follow-up data. There were no statistically significant differences between groups in disease stage. Xerostomia was significantly reduced in group A vs. group B (p = 0.0381). Patients in group A also had significantly less dysphagia. Relapse-free and overall survival were not compromised in group A: 2-year relapse-free survival was 86% vs. 72% in group B (p = 0.361); 2-year overall survival was 88% and 76%, respectively (p = 0.251).

CONCLUSION

This analysis suggests that reducing radiotherapy doses to both parotid glands to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival. Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be standard practice.

Genetic map construction and QTL mapping of resistance to blackleg (Leptosphaeria maculans) disease in Australian canola (Brassica napus L.) cultivars

Genetic map construction and identification of quantitative trait loci (QTLs) for blackleg resistance were performed for four mapping populations derived from five different canola source cultivars. Three of the populations were generated from crosses between single genotypes from the blackleg-resistant cultivars Caiman, Camberra and (AV)Sapphire and the blackleg-susceptible cultivar Westar(10). The fourth population was derived from a cross between genotypes from two blackleg resistant varieties (Rainbow and (AV)Sapphire). Different types of DNA-based markers were designed and characterised from a collection of 20,000 EST sequences generated from multiple Brassica species, including a new set of 445 EST-SSR markers of high value to the international community. Multiple molecular genetic marker systems were used to construct linkage maps with locus numbers varying between 219 and 468, and coverage ranging from 1173 to 1800 cM. The proportion of polymorphic markers assigned to map locations varied from 70 to 89% across the four populations. Publicly available simple sequence repeat markers were used to assign linkage groups to reference nomenclature, and a sub-set of mapped markers were also screened on the Tapidor x Ningyou (T x N) reference population to assist this process. QTL analysis was performed based on percentage survival at low and high disease pressure sites. Multiple QTLs were identified across the four mapping populations, accounting for 13-33% of phenotypic variance (V (p)). QTL-linked marker data are suitable for implementation in breeding for disease resistance in Australian canola cultivars. However, the likelihood of shifts in pathogen race structure across different geographical locations may have implications for the long-term durability of such associations.

Characterisation of MCP-600D and MCP-700D thermoluminescence detectors and their applicability for photoneutron detection

This paper presents the characteristics of two high-sensitive LiF:Mg,Cu,P thermoluminescence detectors (TLDs) named MCP-600D and MCP-700D [thermoluminescence detector (TLD) Poland]. Furthermore, the applicability of both detectors used as a paired system for photoneutron detection in a high-energy photon field at a linear accelerator is shown. For MCP-600D and MCP-700D, the batch homogeneity is within 22 and 14%, respectively (2 SD). Correction for the individual response of each TLD leads to a reproducibility of 5 and 4%, respectively Both TLD types reveal a linear detector response to dose up to 4 Gy. The energy dependence for both is within 2% for 4 and 6 MV photons. For a 15 MV photon beam, the MCP-600D shows a higher response (10%); compared with the MCP-700D (2%). The MCP-600D is capable of detecting extra doses due to photoneutrons in a 15 MV photon exposure; however, the signal for an open field of the used linear accelerator is in the order of the reproducibility. Using a kind of albedo technique allows detection of photoneutrons in the open photon field anyhow. The neutron detection limit is 10 microGy neutron dose per 1 Gy photon dose. Reproducibility of the TLDs, however, requires more than 10 detectors to determine results with an uncertainty of <5%.

Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

In this paper we present the results of a dosimetric evaluation of a 2D ionization chamber array with the objective of its implementation for quality assurance in clinical routine. The pixel ionization chamber MatriXX (Scanditronix Wellhofer, Germany) consists of 32x32 chambers with a distance of 7.6 mm between chamber centres. The effective depth of measurement under the surface of the detector was determined. The dose and energy dependence, the behaviour of the device during its initial phase and its time stability as well as the lateral response of a single chamber of the detector in cross-plane and diagonal directions were analysed. It could be shown, that the detector's response is linear with dose and energy independent. Taking the lateral response into account, two different dose profiles, for a pyramidal and an IMRT dose distribution, were applied to compare the data generated by a treatment planning system with measurements. From these investigations it can be concluded that the detector is a suitable device for quality assurance and 2D dose verifications.

Evaluation of GafChromic EBT prototype B for external beam dose verification

The capability of the new GafChromic EBT prototype B for external beam dose verification is investigated in this paper. First the general characteristics of this film (dose response, postirradiation coloration, influence of calibration field size) were derived using a flat-bed scanner. In the dose range from 0.1 to 8 Gy, the sensitivity of the EBT prototype B film is ten times higher than the response of the GafChromic HS, which so far was the GafChromic film with the highest sensitivity. Compared with the Kodak EDR2 film, the response of the EBT is higher by a factor of 3 in the dose range from 0.1 to 8 Gy. The GafChromic EBT almost does not show a temporal growth of the optical density and there is no influence of the chosen calibration field size on the dose response curve obtained from this data. A MatLab program was written to evaluate the two-dimensional dose distributions from treatment planning systems and GafChromic EBT film measurements. Verification of external beam therapy (SRT, IMRT) using the above-mentioned approach resulted in very small differences between the planned and the applied dose. The GafChromic EBT prototype B together with the flat-bed scanner and MatLab is a successful approach for making the advantages of the GafChromic films applicable for verification of external beam therapy.

Spectral analysis of cyclic fluctuations in haemodynamic parameters in critically ill patients

In critically ill patients haemodynamic parameters are being routinely monitored. All of the fluctuations in blood pressures cannot be visualised since on most monitors the time window is too short and trend curves do not have a sufficient time resolution. Therefore, frequency analysis was applied to an 800-second window. Systemic artery pressure, central venous pressure and pulmonary artery pressure curves of 6 patients were sampled with a frequency of 40 Hz. The signals were transformed into the frequency domain by the Fast Fourier Transform method. Bispectral analysis was applied to determine the origin of higher frequencies. There were three main frequencies present: heart stroke rate, respiratory frequency and a slow frequency (< 0.05 Hz), which was equal to the used infusion rate (2-10 ml/h) of vaso-active drugs. Continuous infusion of short-acting vaso-active drugs delivered by pulsatile diaphragm pumps to produce slow significant fluctuations in especially the arterial blood pressures (range: 5-40 mmHg). The periodicity of these slow fluctuations is not visualised during routine monitoring, so the observer may misinterpret the cause of changes in blood pressure and make inappropriate clinical decisions. A solution for detection of such slow waves is Fast Fourier Transform combined with bispectral analysis.

Evaluation of dynamic performance in liquid-filled catheter systems for measuring invasive blood pressure

Invasive blood pressure measurement is used in patients with unstable haemodynamics. The demand of the accuracy of these measurements is high. The reliability of the reproduced signal strongly depends on the measurement system's dynamic characteristic-its resonance frequency and damping factor. These characteristics were examined with the frequency response method, which is valuable for second and higher order systems. Most of the pressure measuring systems in use in clinical practice have low damping factor (0.1-0.2), which causes high overshoot in systolic pressure values (up to 13%), since putting all the measuring components in a chain reduces the dynamic properties of a single component and the resonance frequency drops drastically from over 100 Hz to even below 10 Hz. One of the solutions to increase the damping ratio is to insert a damping device R.O.S.E. parallel to the tubing. The resonance frequency remains the same, the damping factor increases to around 0.5. Systems with higher damping factors (0.5-0.7) have lower overshoot (1-2%), therefore the blood pressure measurements are more accurate.