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1.

Purpose

The experimental investigation of an optical fiber Bragg grating (FBG) sensor for biomedical application is described. The FBG sensor can be used to measure sound pressure and temperature rise simultaneously in biological tissues exposed to ultrasound. The theoretical maximum values that can be measured with the FBG sensor are 73.0 MPa and 30 °C.

Methods

In this study, measurement of sound pressure up to 5 MPa was performed at an ultrasound frequency of 2 MHz. A maximum temperature change of 6 °C was measured in a tissue-mimicking material.

Results

Values yielded by the FBG sensor agreed with those measured using a thermocouple and a hydrophone.

Conclusion

Since this sensor is used to monitor the sound pressure and temperature simultaneously, it can also be used for industrial applications, such as ultrasonic cleaning of semiconductors under controlled temperatures.
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2.

Purpose

To scrutinize the apoptotic and genotoxic effects of low-intensity ultrasound and an ultrasound contrast agent (SonoVue; Bracco Diagnostics Inc., EU) on human peripheral mononuclear blood cells (PMBCs).

Methods

PMBCs were subjected to a low-intensity ultrasound field (1-MHz frequency; spatial peak temporal average intensity 0.18 W/cm2) followed by analysis for apoptosis and DNA damage (single-strand breaks + double-strand breaks). The comet assay was then repeated after 2 h to examine the ability of cells to repair DNA breaks.

Results

The results demonstrated that low-intensity ultrasound was capable of selectively inducing apoptosis in leukemic PMBCs, but not in healthy cells. The introduction of ultrasound contrast agent SonoVue resulted in an increase in apoptosis in both groups. DNA analysis after ultrasound exposure indicated that ultrasound triggered DNA damage in leukemic PMBCs (66.05 ± 13.36%), while the damage was minimal (7.01 ± 0.89%) in control PMBCs. However, both cell lines demonstrated an ability to repair DNA single- and double-strand breaks 2 h after sonication.

Conclusions

The study demonstrated that low-intensity ultrasound selectively induced apoptosis in cancer PMBCs. Ultrasound-induced DNA damage was observed primarily in leukemic PMBCs. Nevertheless, both cell lines were able to repair ultrasound-mediated DNA strand breaks.
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3.

Purpose

Acoustic radiation force (ARF) elastography has recently become available. The previous animal studies have revealed lung injuries induced by diagnostic ultrasound, but the effects on the lung resulting from exposure to ultrasound with ARF are unknown. This study aimed to assess the risk of lung injury associated with ultrasound with ARF.

Methods

A focused 2.5-MHz transducer that emits ultrasound with ARF was used. A rabbit was anesthetized, and the transducer was placed in the right subcostal region. Exposure settings of mechanical index (MI) 0.80, pulse duration 10 ms, pulse repetition time 5 s, and exposure time 150 s were applied.

Results

One red spot (7 × 6 mm) was observed on the surface of the right lung corresponding to the area of exposure. Alveolar hemorrhage was observed microscopically. This lesion was visible across a range of 20–170 μm in depth from the pleural surface.

Conclusion

The first example of lung hemorrhage induced by ultrasound with ARF was observed in this study. This observation suggests the possibility of lung injury in humans when ARF elastography is applied with the transducer directed toward the lung. Further studies are needed to determine the safety of this modality.
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4.

Purpose

In this study, we aimed to establish a quantitative threshold value in the diagnosis of subacromial impingement syndrome by measuring the thickness of the subacromial bursa during abduction and adduction.

Materials and methods

Forty-five patients with subacromial impingement syndrome and 54 healthy individuals underwent dynamic shoulder ultrasonography. The subacromial bursa, between the supraspinatus tendon margin and peribursal adipose tissue, was measured between the acromion and humeral head at its widest part. The subacromial impingement ratio was calculated by dividing the subacromial bursa thickness during abduction to the subacromial bursa thickness during adduction. Shapiro–Wilk test was used in the assessment of normal distribution of parameters.

Results

The mean subacromial bursa thickness in the abduction position was 1.8 ± 1.1 mm in the study group and 0.9 ± 0.3 mm in the control group. The mean subacromial bursa thickness in the adduction position was 0.9 ± 0.5 mm in the study group and 0.8 ± 0.3 mm in the control group. The subacromial impingement ratio showed a statistically significant difference between groups (p < 0.0001), and the ratio being 2.0 ± 0.5 in the study group and 1.2 ± 0.1 in the control group. For measurements performed in the abduction position, the best cut-off value was calculated as 1.3 mm, and sensitivity and specificity were 70.6 and 85.2%, respectively. The best cut-off value was 1.4 for the subacromial impingement ratio, and sensitivity and specificity were 88.2 and 96.3%, respectively.

Conclusion

Subacromial impingement ratio is a very practical and reliable method in subacromial impingement syndrome diagnosis.
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5.

Purpose

The incidences of perithyroidal lymph nodes (PTLNs) in benign thyroid diseases were investigated.

Methods

A total of 108 patients were divided into 36 with benign thyroid nodules, 33 with Hashimoto’s thyroiditis, 14 with Graves’ disease, 10 with hypothyroidism of undetermined etiology, nine with silent thyroiditis, and six with subacute thyroiditis. We assessed the relationships among PTLNs and these groups, thyroid volume, thyroid parenchyma echogenicity, and anti-thyroid-stimulating hormone receptor, anti-thyroglobulin, and anti-thyroid peroxidase antibodies (TRAb, TgAb, and TPOAb).

Results

The PTLN-positive rates in Hashimoto’s thyroiditis (69.7%), subacute thyroiditis (83.8%), silent thyroiditis (77.8%), and Graves’ disease (35.7%) groups were significantly higher than those in benign thyroid nodules (5.6%) and hypothyroidism of unknown etiology (0%) groups. The PTLN-positive rates were significantly higher in cases with TgAb and/or TPOAb (P < 0.01) and in those with lower parenchyma echogenicity (P < 0.01).

Conclusion

PTLNs were seen in inflammatory thyroid diseases, but were rarely detected in other thyroid diseases. These findings indicate that PTLNs are an indicator for differentiating inflammation of the thyroid. Lower echogenicity of the thyroid, known to correspond to inflammation, showed a correlation with the positive rate of PTLNs. PTLNs in cases of Graves’ disease may be due to coexisting thyroiditis related to TgAb and/or TPOAb.
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6.

Purpose

Indocyanine green (ICG) accumulation in hepatocellular carcinoma means tumors can be located by fluorescence. However, because of light scattering, it is difficult to detect ICG fluorescence from outside the body. We propose a new fluorescence imaging method that detects changes in the intensity of ICG fluorescence by ultrasound-induced temperature changes.

Methods

ICG fluorescence intensity decreases as the temperature rises. Therefore, it should theoretically be possible to detect tissue distribution of ICG using ultrasound to heat tissue, moving the point of ultrasound transmission, and monitoring changes in fluorescence intensity. A new probe was adapted for clinical application. It consisted of excitation light from a laser, fluorescence sensing through a light pipe, and heating by ultrasound. We applied the probe to bovine liver to image the accumulation of ICG.

Results

ICG emits fluorescence (820 nm) upon light irradiation (783 nm). With a rise in temperature, the fluorescence intensity of ICG decreased by 0.85 %/°C. The distribution of fluorescent ICG was detected using an ultrasonic warming method in a new integrated probe.

Conclusion

Modulating fluorescence by changing the temperature using ultrasound can determine where ICG accumulates at a depth, highlighting its potential as a means to locate hepatocellular carcinoma.
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7.

Purpose

The conventional medical ultrasound imaging has a low lateral spatial resolution, and the image quality depends on the depth of the imaging location. To overcome these problems, this study presents a synthetic aperture (SA) ultrasound imaging method using a ring transducer array.

Methods

An experimental ring transducer array imaging system was constructed. The array was composed of 2048 transducer elements, and had a diameter of 200 mm and an inter-element pitch of 0.325 mm. The imaging object was placed in the center of the ring transducer array, which was immersed in water. SA ultrasound imaging was then employed to scan the object and reconstruct the reflection image.

Results

Both wire phantom and ex vivo experiments were conducted. The proposed method was found to be capable of producing isotropic high-resolution images of the wire phantom. In addition, preliminary ex vivo experiments using porcine organs demonstrated the ability of the method to reconstruct high-quality images without any depth dependence.

Conclusion

The proposed ring transducer array and SA ultrasound imaging method were shown to be capable of producing isotropic high-resolution images whose quality was independent of depth.
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8.

Background

In addition to idiopathic shoulder stiffness, secondary shoulder stiffness in particular is often associated with extra-articular subacromial adhesions between the rotator cuff and the surrounding anatomical structures.

Objective

The aim of this article is to present clinical results and complications as well as the surgical technique of extra-articular release in the context of secondary shoulder stiffness.

Material and Methods

Selective review of the literature and presentation of own clinical experience.

Results

Intra-articular and extra-articular release are related to a high patient satisfaction and an improved range of motion. Exact knowledge of the extra-articular anatomy is necessary to prevent iatrogenic lesions of vessels, nerves and the rotator cuff. Compared to patients with a primary stiff shoulder, patients suffering from posttraumatic stiff shoulder benefit more from arthroscopic interventions with intracapsular and extracapsular release.

Conclusion

Restrictions in range of motion of the shoulder can be related to extra-articular adhesions. These adhesions need to be specifically addressed during arthroscopic treatment of stiff shoulders.
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9.

Purpose

Because of the need for rapid, accurate clinical differentiation between malignant and benign ovarian masses, we investigated the diagnostic efficacy of the echo pattern classification used together with transvaginal ultrasound.

Methods

We classified, on the basis of six echo pattern types, transvaginal ultrasound images of 405 ovarian masses treated surgically between January 2011 and December 2012. We compared the resulting classifications to the postoperative histopathologic diagnoses and computed the diagnostic sensitivity and specificity of the echo pattern-based classification for malignancy.

Results

Our review yielded the following echo patterns: type I, n = 61; type II; n = 154; type III, n = 82; type IV, n = 61; type V, n = 34; and type VI, n = 13. Histopathologically, there were 75 borderline malignant/malignant tumors and 330 benign tumors. Diagnostic sensitivity was 80.0 % and specificity was 85.5 % when echo types I–III were categorized as benign and types IV–VI were categorized as malignant. Further, with respect to benign tumors: sensitivity and specificity for chocolate cysts were 85.5 and 88.4 %, respectively, and for dermoid cysts were 67.2 and 97.9 %, respectively.

Conclusions

With the echo pattern classification, ovarian masses can be diagnosed easily and accurately upon transvaginal ultrasound.
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10.

Introduction

To present short-term safety and efficacy data of men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) treated with Aquablation.

Methods

Men with LUTs secondary to BPH (60–150 cc) underwent Aquablation treatment from February 2016 to December 2017 across 17 investigational sites in the USA from two contemporary investigational device exemption (IDE) studies called WATER (NCT02505919) and WATER II (NCT03123250).

Results

One hundred seven males with mean age of 67.3?±?6.5 years were treated with Aquablation; mean prostate volume was 99.4?±?24.1 cc. The pooled results show that large prostates have an average procedure time of less than 36 min and discharge on average 1.6?±?1 days. The IPSS decreased by 16.7?±?8.1 points at 3 months and Qmax increased by 11.2?±?12.4 ml/s. The Clavien-Dindo (CD) grade 2 or higher event rate at 3 months was 29%. A non-hierarchical breakdown for CD events yielded 18% grade 2 and 19% grade 3 or higher.

Conclusion

Men with LUTS secondary to BPH (60–150 cc) in a pooled analysis were treated safely and effectively with Aquablation up to 3 months postoperatively.

Trial Registration

ClinicalTrials.gov identifiers, NCT02505919 and NCT03123250.

Funding

PROCEPT BioRobotics.
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11.

Purpose of Review

Swimmer’s shoulder is the term used to describe the problem of shoulder pain in swimmers. Originally described as supraspinatus tendon impingement under the coracoacromial arch, it is now understood that several different pathologies can cause shoulder pain in competitive swimmers, including subacromial impingement syndrome, overuse and subsequent muscle fatigue, scapular dyskinesis, and laxity and instability.

Recent Findings

Swimmers may develop increased shoulder laxity over time due to repetitive use. Such excessive laxity can decrease passive shoulder stability and lead to rotator cuff muscle overload, fatigue, and subsequent injury in order to properly control the translation of the humeral head. Generalized laxity can be present up to 62% of swimmers, while a moderate degree of multi-directional instability can be present in the majority. Laxity in swimmers can be due to a combination of underlying inherent anatomical factors as well as from repetitive overhead activity.

Summary

The role of excessive laxity and muscle imbalance are crucial in the swimmer’s shoulder and should be well understood since they are the primary target of the training and rehabilitation program.
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12.

Purpose

The aim of this study was to assess the mean value of spleen stiffness measured by Shear wave elastography in healthy patients and its dependence on age, sex, and spleen dimensions, and to evaluate the repeatability of this method.

Methods

The final study group included 59 healthy volunteers without any clinical evidence of liver disease, portal hypertension, hematological disorders, and without any pathological ultrasonographic spleen findings. Each patient underwent abdominal ultrasound examination and elastography of the liver and the spleen.

Results

The mean value of spleen stiffness was 16.6 ± 2.5 kPa. In the group of men (N = 25), it was 17.3 ± 2.7 kPa, and in the group of women (N = 34), it was 16.1 ± 2.2 kPa. The study confirmed no correlation between spleen stiffness and sex, age of patients, and spleen size. Coefficient of repeatability and correlation coefficient between the results of the first and the second measurement showed good but not ideal repeatability of the measurement results.

Conclusion

Our outcomes may be a reference point for evaluating spleen stiffness in research on patients with various illnesses.
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13.

Objective

To investigate the effect of enteral Synbiotic 2000 FORTE® (a mixture of lactic acid bacteria and fibre) on the incidence of ventilator associated pneumonia (VAP) in critically ill patients.

Design

Prospective, randomised, double blind, placebo controlled trial.

Setting

Tertiary referral centre, general Adult Intensive Care Unit (ICU).

Patients and participants

259 enterally fed patients requiring mechanical ventilation for 48 h or more were enrolled.

Intervention

All patients were enterally fed as per a standard protocol and randomly assigned to receive either synbiotic 2000 FORTE® (twice a day) or a cellulose-based placebo for a maximum of 28 days.

Measurements and results

Treatment group (n = 130) was well matched with placebo group (n = 129) for age (mean 49.5 and 50 years, respectively) and APACHE II score (median 17 for both). Oropharyngeal microbial flora and colonisation rates were unaffected by synbiotics. The overall incidence of VAP was lower than anticipated (11.2%) and no statistical difference was demonstrated between groups receiving synbiotic and placebo in the incidence of VAP (9 and 13%, P = 0.42), VAP rate per 1,000 ventilator days (13 and 14.6, P = 0.91) or hospital mortality (27 and 33%, P = 0.39), respectively.

Conclusions

Enteral administration of Synbiotic 2000 FORTE® has no statistically significant impact on the incidence of VAP in critically ill patients.
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14.

Purpose

To investigate whether transperineal ultrasound examination just after full cervical dilatation is determined can predict the mode of delivery.

Methods

This was a prospective observational study of pregnant women. After full cervical dilatation was determined by vaginal examination during labor, transperineal ultrasound was immediately performed, and the head direction (HD), progression distance (PD), and angle of progression (AoP) were measured. The cases were divided into two groups: spontaneous vaginal delivery and operative delivery due to failure of progression. Differences between the groups were statistically analyzed using Student’s t test and Fisher’s exact test.

Results

Of the 50 women, 42 had spontaneous vaginal deliveries and 8 had vacuum extractions. The spontaneous delivery group had significantly higher HD, PD, and AoP values than the vacuum extraction group. The areas under the receiver-operating characteristic curves for the prediction of spontaneous vaginal delivery were 0.850 for HD, 0.827 for PD, and 0.783 for AoP. The optimum cut-off points and positive predictive values were 83° and 92.9 % for HD, 56 mm and 94.9 % for PD, and 146° and 94.3 % for AoP, respectively.

Conclusion

Transperineal ultrasound examination just after full cervical dilatation was determined was useful in predicting spontaneous vaginal delivery.
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15.

Purpose

The aim of this study was to evaluate the testicular parenchyma in pediatric patients with testicular microlithiasis by shear wave elastography (SWE) and compare the values with normal control subjects.

Methods

Twenty-three patients previously diagnosed with testicular microlithiasis under follow-up for 20 ± 11 months were included in the study group. In the control group, 31 patients with no medical history that could affect testicular tissue were prospectively included. Forty-six testes in the study group and 62 testes in the control group were evaluated with gray-scale ultrasound and SWE.

Results

There were no differences in age and testes volume between the study and control groups. The mean SWE values of all testes based on elasticity and speed parameters in the study group were 8.84 ± 2.86 kPa and 1.66 ± 0.26 m/s, respectively. In the control group, mean SWE values were 5.26 ± 1.17 kPa and 1.31 ± 0.14 m/s, respectively. Elasticity values were significantly higher in testes with microlithiasis as compared with the control group (p < 0.001).

Conclusions

SWE evaluation demonstrates the effects of ultrastructural changes in elasticity that are not detected on gray-scale ultrasound. SWE is a more reliable method in follow-up examinations for pediatric testicular microlithiasis.
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16.

Purpose

To explore the microcirculation formation mechanism of contrast-enhanced (CE) ultrasonography imaging performance in rabbits with limb muscle crush injury.

Methods

Seventy-two New Zealand white rabbits were randomly divided into two groups. A limb muscle crush injury model was created by airing a balloon cuff device with a force of 40 kpa. CE ultrasonography parameters were detected in the first group. In vivo microcirculation parameters were detected in the second group. Fine blood vessel diameter and blood flow velocity were calculated before extrusion and 0.5, 2, 6, 24 h, and 3 days after decompression.

Results

Compared with the uninjured muscle, reperfusion of the injured muscles showed early and high enhancement in CE ultrasonography images. The time-intensity curve showed a trend of rapid elevation and gradual drop. Compared with the control group, fine artery and vein diameters in the experimental group were wider and the blood flow velocity was slower, especially in the fine veins.

Conclusion

In vivo microcirculation detection can reflect changes in muscle microvascular diameter and blood flow velocity, which have a correlation with quantitative ultrasound imaging parameters.
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17.

Background

Although chronic shoulder pain is highly prevalent and myofascial trigger points (mTrP) are thought to be found in the majority of patients with shoulder complaints, the influence on the pain mechanism remains unclear. There are only very few controlled clinical studies on the effects of manual trigger point compression therapy.

Objective

This randomized controlled trial (RCT) compared the short-term effects of manual trigger point compression therapy (n = 6) with manual sham therapy (n = 6) in patients with unilateral shoulder pain due to myofascial syndrome (MFS).

Material and methods

The measurement data were collected before and after two sessions of therapy. Pressure pain thresholds (PPT) of mTrP and symmetrically located points on the asymptomatic side were measured together with neutral points in order to detect a potential unilateral or generalized hyperalgesia. Additionally, the pain was assessed on a visual analog scale (VAS) at rest and during movement and the neck disability index (NDI) and disabilities of the arm, shoulder and hand (DASH) questionnaires were also completed and evaluated.

Results

Both treatment modalities led to a significant improvement; however, the manual trigger point compression therapy was significantly more effective in comparison to sham therapy, as measured by different parameters.

Conclusion

The significant improvement of PPT values in the interventional group even at sites that were not directly treated, indicates central mechanisms in pain threshold modulation induced by manual compression therapy. The weaker but still measurable effects of sham therapy might be explained by the sham modality being a hands on technique or by sufficient stimulation of the trigger point region during the diagnostics and PPT measurements.
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18.

Purpose

To investigate the feasibility of acoustic radiation force impulse imaging in differentiation of endometriomas and hemorrhagic ovarian cysts.

Materials and methods

We evaluated 84 ovarian cysts with high internal echogenicity diagnosed in 70 consecutive women. We excluded simple cysts and hemorrhagic cysts containing septations or mural nodules with detectable flow on Doppler ultrasonography. We obtained the elastographic shear wave velocity (SWV) value of the cysts that could be endometriomas or hemorrhagic ovarian cysts.

Results

Among the 78 ovarian cysts in 70 women without any septation or mural nodule, there were 42 endometriomas and 36 hemorrhagic ovarian cysts. Analysis of median SWV values of the ovarian cysts showed that the endometriomas had considerably higher levels of stiffness compared to the hemorrhagic ovarian cysts [median SWV 4.20 ± 0.42 vs 2.54 ± 1.04 m/s, p < 0.001]. A SWV cutoff value greater than 3.81 m/s yielded sensitivity and specificity values of 82.1 and 79.2 % respectively, for differentiation of endometriomas from hemorrhagic ovarian cysts.

Conclusion

Sonoelastography is a novel imaging technique that enables us to evaluate the stiffness of adnexal lesions. The accurate discrimination of endometriomas and hemorrhagic ovarian cysts is important for avoiding unnecessary surgical procedures. ARFI imaging has a high sensitivity and specificity for distinguishing endometrioma from hemorrhagic ovarian cysts.
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19.

Purpose

To evaluate extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of severe obstructive sleep apnea (OSA) on retrobulbar blood flow.

Methods

Between February 2014 and September 2015, 30 patients with severe OSA (apnea–hypopnea index (AHI) > 30) and 28 controls were prospectively included in this study. Intraocular pressure (IOP) was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels.

Results

The mean AHI score for the OSA group was 63.2 ± 21.5 per hour. The IOP values were significantly higher in the severe OSA group (p < 0.05). The central retinal artery peak systolic velocity (PSV) (p < 0.05) and end-diastolic velocity (EDV) (p < 0.02), and the ophthalmic artery (OA) PSV and EDV, were found to be significantly lower in the OSA group (p < 0.05).

Conclusion

Severe OSA causes an increase in IOP and a decrease in flow velocity in the retrobulbar circulation.
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20.

Introduction

Trimetazidine (TMZ) has been shown to reduce angina symptoms and to increase exercise capacity in randomized clinical trials, but more extensive data would be useful to assess its effects in real-world clinical practice and in patients with different durations of disease.

Methods

CHOICE-2 was a Russian, multicenter, 6-month, open-label, prospective observational study that assessed the effect of adding TMZ modified release 35 mg bid to antianginal treatment in a real-world setting. The present analysis of CHOICE-2 results explored the effects of adding TMZ to background antianginal therapies with regard to the duration of stable angina.

Results

A total of 741 patients with known durations of disease were divided into four groups according to stable angina pectoris (AP) duration, ranging from less than 1 year to more than 9 years. Addition of TMZ led to a significant decrease in the frequency of angina attacks and in the use of short-acting nitrates in all groups. In patients with recently diagnosed angina (AP duration < 1 year), the average number of angina attacks per week decreased significantly from 3.75 ± 4.63 to 0.67 ± 1.51 and in those with advanced disease (AP duration > 9 years) from 5.63 ± 5.24 to 1.32 ± 2.07. Angina-free walking distance also improved significantly. Addition of TMZ also improved patient well-being. Results were achieved rapidly (within 2 weeks), were maintained over 6 months, and were obtained in all patient groups regardless of angina duration.

Conclusion

TMZ added to other antianginal therapies proved to be effective for reducing angina attacks and short-acting nitrate use, increasing angina-free walking distance, and improving patient well-being in a real-life setting, irrespective of angina duration, including patients with recently diagnosed angina. This provides an opportunity for intensification of treatment early on in the disease process, with the aim of decreasing angina burden and improving patient quality of life.

Funding

Servier.

Trial Registration

ISRCTN identifier ISRCTN65209863.

Plain Language Summary

Plain language summary available for this article.
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