Advances in Anterior Cruciate Ligament Injury, Reconstruction and Rehabilitation

Another Special Issue dedicated to the anterior cruciate ligament (ACL) of the knee joint [...].

Outcomes in revision total knee arthroplasty (Review)

Revision total knee arthroplasty (TKA) is a challenging surgical procedure. Although good results are presented, the outcomes are worse in comparison with those of primary TKA, with a higher failure rate. The main reasons for the failure of revision TKA include: sepsis, loosening and instability. There are multiple variables linked to these results, and it is difficult to determinate the exact cause as it is often a multifactorial issue. These variables may be related to the quality of the index-procedure (TKA), to the revision procedure or to patient characteristics. The purpose of this review was to highlight the outcomes of revision knee arthroplasty and main factors that may influence the results. Considerable progress has been made during the last 30 years regarding infection treatment and prevention, complex revision prosthetic design and surgical technique development. Although the outcomes have improved over time, patients who undergo revision TKA may need further re-operations in the future.

Historical overview of hip arthroplasty: From humble beginnings to a high-tech future

Surgery of the arthritic hip was not an easy task in the previous centuries, lots of operations being followed very closely by complications and failures. Nowadays, hip arthroplasty is considered "the operation of the century". This review follows the evolution of surgery on the arthritic hip, with emphasis on arthroplasty. Acknowledging the history of this operation, one can better prepare its evolution and future directions of research. The final chapter briefly describes the current trends and future perspectives.

Effect of COVID-19 Pandemic on Orthopedic Surgery in Three Centers from Romania

The COVID-19 pandemic has put an enormous burden on healthcare systems. As a direct consequence, many elective procedures were cancelled and available resources were relocated to emergencies and COVID-19 patients. We aimed to analyze the impact on orthopedic surgery in Romania. We performed a retrospective analysis of orthopedics and trauma cases admitted over the first six months of 2019 and 2020 in three representative clinics. In total, there were 1900 patients: 1241 from Timisoara, 216 from Cluj-Napoca, and 443 from Bucharest. In April, activity for all cases in the regional trauma center dropped to 23.8% and stopped in the other two. No arthroscopies or elective joint replacements were performed in April. By June, hospital admissions resumed for trauma cases while arthroscopies and joint replacements still lagged behind.

Platelet Aggregation Inhibitors and Anticoagulants Delay Surgery for Hip Fractures

Background: we aimed to analyze the influence of antithrombotic medication in delaying surgery for fragility hip fractures; Method: a total of 312 consecutive hip fracture cases over 55 years who underwent surgery in our Orthopedic Clinic; Results: of these, 90 patients received chronic antithrombotic medication. There were no differences between the medicated group and controls (n = 222) regarding age, gender, type of fracture and haemoglobin at admittance. However, median time to surgery was significantly longer in the medicated group: 4(3–6) days compared to 2(1–4) (p < 0.0001). By type of medication, time to surgery was: 3(1–4) days for acetylsalicylic acid (n = 44), 6(5.25–7.75) days for clopidogrel (n = 15), 4.5(4–7) days for acenocoumarin (n = 18) and 5(4–7.25) days for novel direct oral anticoagulants (n = 13). The Charlson comorbidity index was significantly higher in the medicated group: 5 [4–5] versus 4 [3–5]. There were no differences in transfusions except for fresh frozen plasma, which was administered more in the medicated patients; Conclusions: the prevalence of platelet aggregation inhibitors and anticoagulant use among fragility hip fracture patients is high, with almost a third using some form of antithrombotic medication. This may significantly lengthen time to surgery.

Are physical therapy pain levels affected by surgical approach in total hip arthroplasty? A randomized controlled trial

The main objective of this study was to evaluate the difference in pain levels during postoperative physical therapy pathways in patients who underwent a cement less total hip replacement either through a muscle sparing direct anterior approach (DAA), or the classic trans-gluteal lateral approach (LA). One hundred and twelve (112) patients were randomized into two equal groups. Baseline values of myoglobin levels were acquired prior to surgery and repeated at 6 hours postoperatively as a biomarker for muscle damage. Pain levels during the first passive and consecutive 3 active physical therapy sessions were noted using a visual analogue-numeric scale (VAS). Pain levels were also acquired at 6 weeks, 3 months, 6 months and 1 year, following a 20-meter (65.6 feet) walking test. Postoperative myoglobin (ng/mL) levels were significantly higher (p< 0.05) in the LA group (335.05±83.54) then the DAA group (237.71±57.54). Pain levels were significantly lower (p<0.001) in the DAA group for both passive (2.5±1.45 vs. 4.28±2.19) and active physical therapy sessions and there was a positive correlation between postoperative myoglobin levels and pain levels until 6 postoperative weeks. There was no significant difference in demographics between the two groups except for gender distribution. The direct anterior approach’s main advantage of being a minimally invasive muscle sparing technique is showing a better rehabilitation experience with lower pain levels during passive and active physical therapy when compared to the classic trans-gluteal lateral approach.

Cross-cultural adaptation and validation of the Romanian knee disability and osteoarthritis outcome score for joint replacement (KOOSJR)

Aim

To perform validation of the Romanian Knee disability and Osteoarthritis Outcome Score for Joint Replacement (KOOSJR).

Method

Ninety-six patients (101 knees) with advanced osteoarthritis (OA) scheduled for total knee replacement completed Romanian translations of KOOSJR and IKDC (International Knee Documentation Committee – subjective knee form) and Euroqol EQ-5D-5 L, and the treating physician completed the original knee society score (KSS).

Results

Average age was 66.4 (range 50–83) years and male to female ratio 1:3.76. There was moderate correlation between the test-retest (average 4 days) KOOSJR (r = 0.618, n = 45) and IKDC (r = − 0.671, n = 99), weak between KOOSJR and EQ-5D-5 L Index (r = − 0.431, n = 100) and VAS (r = − 0.364, n = 99) and very weak to KSS score (r = − 0.133, n = 98) and function (r = − 0.072, n = 97) For the first KOOSJR, Cronbach’s alpha was 0.816 and intraclass correlation coefficient (ICC) 0.816 (95% CI 0.755–0.866) for average measures. For the retest, Cronbach’s alpha was 0.841 (95% CI 0.760–0.903) for averages.

Conclusion

The Romanian Knee disability and Osteoarthritis Outcome Score for Joint Replacement (KOOSJR) is a valid, reliable, consistent and reproducible clinical score for patients with OA requiring arthroplasty.

Cross-cultural adaptation and validation of the Romanian International Knee Documentation Committee-subjective knee form

Aim

We aimed to translate and cross-culturally adapt the International Knee Documentation Committee—subjective knee form (IKDC) in Romanian.

Method

The original (US) IKDC—subjective knee form was translated according to recommended guidelines. Validity was tested using Spearmans’s correlation coefficient between score sand test-retest reproducibility. Reliability and internal consistency were determined using Cronbach’s alpha coefficient and intraclass correlation coefficient (ICC).

Results

A total of 106 data sets were available for processing. The average age was 52 years and the male to female ratio was 40:66. Fifty-five subjects repeated the form after an average of 4 days. There were no floor or ceiling effects (range 3.4–74.7). There was a strong correlation between the first and repeated administration of the IKDC—subjective knee form (r = 0.816, n = 50) and moderate compared to Tegner-Lysholm knee rating scale (r = 0.506, n = 102), KOOSJR (Knee disability and Osteoarthritis Outcome Score for Joint Replacement, r =  − 0.622, n = 96), EuroqolEQ-5D-5L Index (r = 0.633, n = 100) and visual analogue scale VAS (r = 0.484, n = 99). Internal consistency was moderate with Cronbach’s alpha 0.611 (n = 102) and ICC 0.611 for average measures (95% CI 0.493–0.713).

Conclusion

The Romanian translation of the IKDC—subjective knee form is a valid, consistent and reproducible outcome measure in patients with knee pain and dysfunction.

Combined Anterolateral, Anterior, and Anteromedial Ankle Impingement in an Adolescent Soccer Player: A Case Report and Review of the Literature

A unique case of combined anterolateral, anterior, and anteromedial ankle impingement in an adolescent soccer player is presented in this article. To the best of our knowledge, this is the only report of circumferential, massive, anterior ankle impingement in children described in the literature. The importance of proper diagnosis and treatment of such a lesion is illustrated in this case report. We also emphasize that clinical examination combined with 3D computed tomography scan reconstruction is an excellent and cost-effective imaging modality that can help with the diagnosis of anterior ankle impingement. Finally, open surgical treatment showed excellent results in an elite athlete.

Lymphocyte and Neutrophil to Lymphocyte Ratio do not Predict Mortality in Hip Fracture Patients

Our study aimed to assess whether admission hemoglobin, lymphocyte count and neutrophil to lymphocyte ratio (N/R) can predict 1-year survival in patients with hip fractures. In the study, data from 54 patients with femoral neck fractures, 119 with trochanteric fractures respectively 24 with subtrochanteric fractures was analyzed. All the included patients were older than 55 years and were followed up to 2 years or until the decease occurred. The following parameters were recorded in patients with femoral neck, trochanteric respectively subtrochanteric fractures: average age: 76; 79.7 respectively 73.3 years; male to female ratio: 1:2.86; 1:3.1 respectively 1:2; average hemoglobin at admission: 13.13, 11.56 respectively 11.81; average lymphocyte count: 1.69; 1.7 respectively 1.75. At the logistic regression model built having the death as outcome and the lymphocytes respectively the N/L as predictors, we did notfound any significant associations in neither of the groups (p values of 0.837, 0.171 and 0.162 for lymphocyte and 0.920, 0.764 and 0.168 for N/L respectively). When age, gender and hemoglobin at admittance were accounted for, only for fractures of the trochanteric region age was predictive of survival with p[0.001. Our study showed no prediction for survival of hip fracture patients by using perioperatively collected total lymphocyte count and neutrophil to lymphocyte ratio.

Clinical outcomes after ACL reconstruction with free quadriceps tendon autograft versus hamstring tendons autograft. A retrospective study with a minimal follow-up two years

OBJECTIVE

The aim of this retrospective study was to compare the clinical outcomes of anatomic single bundle ACL reconstruction using either a free quadriceps tendon autograft or a quadrupled hamstring autograft with a minimum follow-up of 24 months.

METHODS

Consecutive patients undergoing ACL reconstruction using either a free quadriceps tendon autograft or hamstring tendon autograft from January 2013 to December 2014 were included. ACL reconstruction was done in all patients due to isolated ACL tears. Patients with associated cartilage lesions > Outerbridge III, meniscal lesions in need of meniscectomy or repair as well as patients with prior knee surgery on the affected or contralateral knee were excluded. The primary outcome evaluation was the side-to-side difference in instrumented Lachman testing. Secondary outcome evaluation consisted in the Lysholm, modified Cincinnati and SF-36 scores. Side-to-side difference in range of motion and thigh diameter was also documented.

RESULTS

After applying the inclusion/exclusion criteria, a total of 82 patients were identified and 72 (87.8%) presented to the hospital for follow-up. There were 39 patients with quadriceps graft (30.64 ± 8.71, range: 18-53 years) and 33 patients with hamstrings (28.60 ± 6.74, range: 18-46 years). No statistically significant difference between groups was detected with regard to KT-1000 measurements (p = 0.326). No significant difference was found between the mean postoperative Lysholm (p = 0.299), the modified Cincinnati (p = 0.665) and the general SF-36 scores between groups (p = 0.588). Less side-to-side thigh diameter difference was noted in the quadriceps graft group (p = 0.026).

CONCLUSION

In conclusion, similar clinical results, in terms of stability and subjective measures, can be obtained after ACL reconstruction both with a free quadriceps and a 4-strand hamstring tendons autograft.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Use of clinical and computed tomography findings to assess long-term unsatisfactory outcome after femoral head and neck ostectomy in four large breed dogs

Femoral head and neck ostectomy (FHNO) is a salvage surgical procedure intended to eliminate hip joint laxity associated pain in the immature dog, or pain due to secondary osteoarthritis in the mature dog. The outcome of the procedure is associated with the size of the dog but the cause of a generally poorer outcome in larger breeds has not been determined. The objective of this study was to assess the long-term results of FHNO associated with unsatisfactory functional outcome by means of clinical examination and computed tomography (CT) scanning. Four large mixed breed dogs underwent FHNO in different veterinary clinics. Clinical and CT scanning evaluations were carried out long time after the procedures had been done. Hip pain, muscle atrophy, decreased range of motion and chronic lameness were observed at clinical examination. Extensive remodelling, unacceptable bone-on-bone contact with bony proliferation involving the femoral neck and acetabulum, but also excessive removal with bone lysis were observed by CT scanning. Revision osteotomy was performed in one dog. Deep gluteal muscle interposition was used, but no improvements were observed postoperatively. This is the first report on the evaluation of three-dimensional CT reconstructions of the late bone remodelling associated with poor clinical outcome in large dogs. The study shows that FHNO could lead to severe functional deficits in large breed dogs. An extensive follow-study is necessary to more accurately determine the frequency of such complications.

Joint hyperlaxity prevents relapses in clubfeet treated by Ponseti method-preliminary results

PURPOSE

The aim of the study was to evaluate the role of joint hyperlaxity (by Beighton score) as a protective factor for clubfoot relapse.

METHODS

Patients with idiopathic clubfoot treated with the Ponseti method between January 2004 and December 2012, without other congenital foot deformity, and not previously treated by open surgery were included in either the Relapse group (n = 23) if it was a clubfoot relapse or the Control group (n = 19) if no relapse was noted. Joint laxity was evaluated using the Beighton score at the latest follow-up against the Normal group (n = 22, children matched by sex and age without clubfoot deformity).

RESULTS

We found a significantly higher joint laxity in the Control group (4.58, 95% confidence interval [CI]: 2.1-7.06) as compared to the Relapse (3.17, 95% CI: 1.53-4.81, p = 0.032) and Normal (3.14, 95% CI: 1.78-4.5, p = 0.03) groups. The univariate logistic regression showed a 5.28-times increase in the risk of relapse for a Beighton score lower than 4/9 points (odds ratio = 5.28; 95% CI = 1.29-21.5; p = 0.018).

CONCLUSIONS

Joint hyperlaxity could be a protective factor for clubfoot relapse.

Transitioning to the direct anterior approach in total hip arthroplasty. Is it a true muscle sparing approach when performed by a low volume hip replacement surgeon?

PURPOSE

We conducted this study to establish if the transition from a lateral approach (LA) to the direct anterior approach (DAA) for a low volume hip arthroplasty surgeon during the steep learning curve can be performed maintaining the muscle sparing approach of the DAA without increasing the complication rates.

METHODS

In this controlled, prospective, randomized clinical study we investigated 70 patients (35 DAA, 35 LA) with similar demographics that underwent a total hip arthroplasty. Assessment of the two approaches consisted of determining the invasiveness through serum markers for muscle damage (i.e. myoglobin, creatine kinase and lactate dehydrogenase), the operative parameters such as post-operative pain and rescue medication consumption, the component positioning and complication rates.

RESULTS

Post-operative myoglobin levels were higher (p < 0.001) in the LA group (326.42 ± 84.91 ng/mL) as compared to the DAA group (242.80 ± 71.03 ng/mL), but with no differences regarding other biomarkers for muscle damage. Pain levels were overall lower in the DAA group, with a statistical and clinical difference during surgery day (p < 0.001) associated with lower (p < 0.001) rescue medication consumption (median 1 (1; 3) mg morphine vs. 3 (2; 4) mg morphine). Most patients in the LA group reported chronic post-operative pain throughout all three evaluated months, while the majority of patients in the DAA group reported no pain after week six. Component positioning did not differ significantly between groups and neither did complication rates.

CONCLUSION

The DAA can be transitioned from the LA safely, without higher complication rates while maintaining its muscle spearing advantages when performed by a low volume hip arthroplasty surgeon.

Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts

Objective

The objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft.

Patients and methods

A total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test.

Results

Supplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group.

Conclusion

The use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft.

Level of Evidence

Level I Therapeutic study

Novel Surgical Technique for Bone Marrow Lesion — Case Report

Introduction: Bone marrow lesions (BMLs) are commonly described as magnetic resonance imaging (MRI) findings associated with stress injuries or trauma. The presence of BMLs closely correlates with pain and rapid joint deterioration. Case presentation: A 51-year-old healthy man presented to our clinic with severe knee pain due to BMLs. After 3 months of conservative treatment, arthroscopy and subchondroplasty (SCP) of the medial femoral condyle was performed. The IKDC (International Knee Documentation Committee) score improved from 39.9 to 66.7 at 6 months, and to 87.4 at 1 year after surgery. The KOOS (Knee Injury and Osteoarthritis Outcome) score improved from 38.5 to 77.7 at 6 months, and to 92.6 at 1 year after surgery. The Tegner Lysholm score improved from 23 to 80 at 6 months, and to 95 at 1 year after surgery. Conclusion: SCP may provide a viable approach to reduce pain associated with BML, with minimal risk of significant complications.

ACL Surgical Technique — Staying Out of Trouble

The incidence of ACL tear and reconstruction has increased over time, and failure of ACL reconstruction is not perfectly defined among surgeons. Atraumatic failure of ACL surgery represents approximately 70% of causes, and occurs in diagnostic errors, technical errors and problems of ACL graft integrations. Regarding surgical technique, we should answer certain questions about our choice of surgery, tunnel position, graft type, graft suture, tensioning the graft, and how we deal with certain incidents or intraoperative accidents. The purpose of this article is to review the current information and trends of ACL reconstruction, and presents some tips and tricks we use in our current practice.

Single- or Double-Bundle Technique in the Anterior Cruciate Ligament Reconstruction — Current Concepts and Review of the Literature

The treatment for anterior cruciate ligament (ACL) deficient knee consists in its surgical reconstruction. There are several available and validated techniques, but there are still numerous questions to be answered concerning the best approach in terms of stability, functional outcome, and avoiding further damage in the knee. This paper sought to analyze the studies published in the literature comparing the outcomes of ACL restoration with single-bundle versus double-bundle techniques. The results demonstrate that even if biomechanical studies find an increased steadiness with double-bundle ACL reconstruction, there seems to be no clinical or functional benefit compared with single-bundle reconstruction.

Outcomes in Anterior Cruciate Ligament Reconstruction Surgery

Improving the outcomes in reconstructive surgery of the anterior cruciate ligament (ACL) requires a rigorous and permanent assessment of specific parameters. Therefore, we can increase the degree of reproducibility of the procedure and identify particular aspects in order to achieve an adequate and individualized therapeutic approach for each case. In order to accomplish this goal, the use of complex means (scores) of quantifying results is required. That includes objective means of verifying the parameters in knee surgery, and a subjective evaluation of the patient in order to compare the results.

Primary Anterior Cruciate Ligament Reconstruction. How Do We Do It?

Anterior cruciate ligament (ACL) tears are frequently seen in current practice mostly affecting the young, active subjects, and usually require ligament reconstruction in order to restore normal knee kinematics. As worldwide interest in anatomic reconstruction grew over the last decade, we have also refined our technique in order to restore the anatomical function as near to the normal as possible. This anatomical restoration concept is believed to prevent the onset of osteoarthritis, which the non-anatomic reconstructions fail to attain. The knowledge gained from the ACL anatomy, function and kinematics has helped in developing the current anatomic methods of reconstruction, which take into account patient anatomy, the rupture pattern, as well as the comorbidities. We present our approach to anatomical single- and double-bundle ACL reconstruction.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With a Free Quadriceps Tendon Autograft

Anatomic double-bundle anterior cruciate ligament (ACL) reconstruction aims to restore the 2 functional bundles of the ACL in an attempt to better reproduce the native biomechanics of the injured knee and promote long-term knee health. However, this concept is not fully accepted and is not performed on a standard basis. In addition, the superiority of this technique over the conventional single-bundle technique has been questioned, especially the long-term clinical results. One of the down sides of the double-bundle reconstruction is the complexity of the procedure, with increased risks, operative time, and costs compared with the single-bundle procedure. Also, the revision procedure, if necessary, is more challenging. We propose a technique that has some advantages over the traditional double-bundle procedure, using a single femoral tunnel, 2 tibial tunnels, and a free quadriceps tendon autograft.

Free Bone Plug Quadriceps Tendon Harvest and Suspensory Button Attachment for Anterior Cruciate Ligament Reconstruction

The most commonly used autografts for anterior cruciate ligament reconstruction are the bone-patellar tendon-bone and hamstring tendons. Each has its advantages and limitations. The bone-patellar tendon-bone autograft can lead to more donor-site morbidity, and the hamstring autograft can be unpredictable in size. The quadriceps tendon, with or without a bone block, has been described as an alternative graft source and has been used especially in revision cases, but in recent years, it has attracted attention even for primary cases. We report a technique for harvesting a free bone quadriceps tendon graft and attaching an extracortical button for femoral fixation for anterior cruciate ligament reconstruction.

Incidence and treatment of intra-articular lesions associated with anterior cruciate ligament tears

The aim of the study is to retrospectively review the patients admitted and treated in the “Alexandru Rădulescu” Orthopedics and Traumatology Clinic, Cluj-Napoca for an anterior cruciate ligament tear over a 2-year period and document the intra-articular lesions found at arthroscopy as well as the treatment used for these associated lesions.

Chronic therapy with metoprolol attenuates cardiomyocyte apoptosis in dogs with heart failure

OBJECTIVES

The purpose of this study was to determine if therapy with beta-blockade is associated with reduced cardiomyocyte apoptosis.

BACKGROUND

Chronic treatment with beta-adrenergic blocking agents has been shown to improve left ventricular (LV) ejection fraction and attenuate progressive LV remodeling in heart failure (HF). Cardiomyocyte apoptosis has also been shown to occur in the failing heart.

METHODS

Moderate HF was produced in 14 dogs by intracoronary microembolizations. Dogs were randomized to three months therapy with metoprolol (MET, 25 mg twice daily, n = 7) or to no therapy at all (n = 7). At the end of three months, dogs were sacrificed, and nuclear DNA fragmentation (nDNAf), a marker of apoptosis, was assessed in LV tissue using the TUNEL assay. The number of cardiomyocytes with positive nDNAf labeling per 1,000 was quantified in LV regions bordering old infarcts and in regions remote from infarcts. Endonuclease activity and expression of the antiapoptotic protein Bcl-2 and the proapoptotic proteins Bax and caspase-3 were also evaluated in LV tissue.

RESULTS

The number of nDNAf events per 1,000 cardiomyocytes was lower in dogs treated with MET compared with untreated dogs with HF in the border regions (0.35 +/- 0.07 vs. 5.32 +/- 0.77, p < 0.001) as well as the remote regions (0.07 +/- 0.05 vs. 0.39 +/- 0.12, p < 0.05). Endonuclease activity was also significantly lower in MET-treated compared with untreated dogs (25 +/- 3 vs. 37 +/- 2 ng [3H]DNA rendered soluble/min/mg protein). Western blotting for Bcl-2, Bax and caspase-3 showed increased expression of Bcl-2, decreased expression of caspase-3 and no change in Bax in MET-treated compared with untreated dogs.

CONCLUSIONS

Chronic therapy with MET attenuates cardiomyocyte apoptosis in dogs with moderate HF. Attenuation of ongoing cardiomyocyte loss through apoptosis may be one mechanism through which beta-blockers elicit their benefits in HF.

Effects of long-term therapy with bosentan on the progression of left ventricular dysfunction and remodeling in dogs with heart failure

OBJECTIVES

In this study, we examined the effects of long-term therapy with bosentan on the progression of LV dysfunction and remodeling in dogs with moderate HF.

BACKGROUND

Acute intravenous administration of bosentan, a mixed endothelin-1 type A and type B receptor antagonist, was shown to improve left ventricular (LV) function in patients and dogs with heart failure (HF).

METHODS

Left ventricular dysfunction was induced by multiple, sequential intracoronary microembolizations in 14 dogs. Embolizations were discontinued when LV ejection fraction (EF) was between 30% and 40%. Dogs were randomized to three months of therapy with bosentan (30 mg/kg twice daily, n = 7) or no therapy at all (control, n = 7).

RESULTS

In untreated dogs, EF decreased from 35 +/- 1% before initiating therapy to 29 +/- 1% at the end of three months of therapy (p = 0.001), and LV end-diastolic volume (EDV) and end-systolic volume (ESV) increased (EDV: 71 +/- 3 vs. 84 +/- 8 ml, p = 0.08; ESV: 46 +/- 2 vs. 60 +/- 6 ml, p = 0.03). By contrast, in dogs treated with bosentan, EF tended to increase from 34 +/- 2% before initiating therapy to 39 +/- 1% at the end of three months of therapy (p = 0.06), and EDV and ESV decreased (EDV: 75 +/- 3 vs. 71 +/- 4 ml, p = 0.05; ESV: 48 +/- 2 vs. 43 +/- 3 ml, p = 0.01). Furthermore, compared with untreated dogs, dogs treated with bosentan showed significantly less LV cardiomyocyte hypertrophy and LV volume fraction of interstitial fibrosis.

CONCLUSIONS

In dogs with moderate HF, long-term therapy with bosentan prevents the progression of LV dysfunction and attenuates LV chamber remodeling. The findings support the use of mixed endothelin-1 receptor antagonists as adjuncts to the long-term treatment of HF.