Biomarkers of inflammation and coagulation after minimally invasive mitral valve surgery: a prospective comparison to conventional surgery.

OBJECTIVES: Minimally invasive cardiac surgery techniques are increasingly used but have longer cardiopulmonary bypass time, which may increase inflammatory response and negatively affect coagulation. Our aim was to compare biomarkers of inflammation and coagulation as well as transfusion rates after minimally invasive mitral valve repair and mitral valve surgery using conventional sternotomy. DESIGN: A prospective non-randomized study was performed enrolling 71 patients undergoing mitral valve surgery (35 right mini-thoracotomy and 36 conventional sternotomy procedures). Blood samples were collected pre- and postoperatively to assess inflammatory response. Thromboelastometry (ROTEM) was performed to assess coagulation, and transfusion rates were monitored. RESULTS: The minimally invasive group had longer cardiopulmonary bypass times compared to the sternotomy group: 127 min ([115-146] vs 79 min [65-112], p < 0.001) and were cooled to a lower temperature during cardiopulmonary bypass, 34 °C vs 36 °C (p = 0.04). IL-6 was lower in the minimally invasive group compared to the conventional sternotomy group when measured at the end of the surgical procedure, (38 [23-69] vs 61[41-139], p = 0.008), but no differences were found at postoperative day 1 or postoperative day 3. The transfusion rate was lower in the minimally invasive group (14%) compared to full sternotomy (35%, p = 0.04) and the chest tube output was reduced, (395 ml [190-705] vs 570 ml [400-1040], p = 0.04). CONCLUSIONS: Our data showed that despite the longer use of extra corporal circulation during surgery, minimally invasive mitral valve repair is associated with reduced inflammatory response, lower rates of transfusion, and reduced chest tube output.

Mitral Annular Disease at Cardiac MRI: What to Know and Look For.

Accurate evaluation of the mitral valve (MV) apparatus is essential for understanding the mechanisms of MV disease across various clinical scenarios. The mitral annulus (MA) is a complex and crucial structure that supports MV function; however, conventional imaging techniques have limitations in fully capturing the entirety of the MA. Moreover, recognizing annular changes might aid in identifying patients who may benefit from advanced cardiac imaging and interventions. Multimodality cardiovascular imaging plays a major role in the diagnosis, prognosis, and management of MV disease. Transthoracic echocardiography is the first-line modality for evaluation of the MA, but it has limitations. Cardiac MRI (CMR) has emerged as a robust imaging modality for assessing annular changes, with distinct advantages over other imaging techniques, including accurate flow and volumetric quantification and assessment of variations in the measurements and shape of the MA during the cardiac cycle. Mitral annular disjunction (MAD) is defined as atrial displacement of the hinge point of the MV annulus away from the ventricular myocardium, a condition that is now more frequently diagnosed and studied owing to recent technical advances in cardiac imaging. However, several unresolved issues regarding MAD, such as the functional significance of pathologic disjunction and how this disjunction advances in the clinical course, require further investigation. The authors review the role of CMR in the assessment of MA disease, with a focus on MAD and its functional implications in MV prolapse and mitral regurgitation. ©RSNA, 2024 Supplemental material is available for this article. See the invited commentary by Stojanovska and Fujikura in this issue.

Rare Case of Disseminated Histoplasmosis Mitral Valve Endocarditis in Florida.

BACKGROUND Histoplasma capsulatum is prevalent in the mid-eastern United States and is an environmental fungus that causes human infection by the inhalation of its spores. It is commonly associated with areas containing large amounts of bird excrement and can survive for years in the soil. Only 1% of infected individuals develop disseminated histoplasmosis or Histoplasma endocarditis. CASE REPORT A 61-year-old man with atrial fibrillation had 8 months of fatigue, low-grade fevers, night sweats, and unexplained weight loss presented to the Emergency Department. He worked and lived in Central Florida and although he raised cattle, he denied exposure to birds or bats with regularity. A transesophageal echocardiogram confirmed a sessile echo density on the atrial surface of the mitral valve. His microbial Karius cell-free DNA test from his blood sample was positive for Histoplasma capsulatum, and he was immediately given intravenous liposomal amphotericin for 2 weeks. A tissue valve was used to successfully replace his mitral valve along with a coronary artery bypass and a maze procedure for his persistent atrial fibrillation and atrial flutter. The diagnosis of mitral valve endocarditis from disseminated histoplasmosis was confirmed by pathological analysis, and he was sent home on long-term itraconazole maintenance treatment. CONCLUSIONS Surgical intervention in combination with anti-fungal medication can be a lifesaving intervention for disseminated histoplasmosis. A thorough history is particularly important when evaluating a patient with an unknown infectious source, especially assessing for risk factors, including exposure to environmental factors, workplace, and animals.

Use of methylphenidate and reporting of valvular heart disease: Global pharmacovigilance analysis in children and adults.

INTRODUCTION: Methylphenidate (MPH) is a common treatment of attention-deficit/hyperactivity disorder (ADHD). Concern has been raised regarding its cardiovascular safety, partly in relation with its micromolar affinity for the 5-HT2B receptor, whose activation may result in valvular heart disease (VHD). METHODS: To explore the association between the use of MPH and VHD reporting, we performed a disproportionality analysis within the WHO global safety database (VigiBase) using data, since inception until March 6th 2024, from: (i) the full database and (ii) different age groups (children/adolescents 6-17 years; adults 18-64 years). To avoid competition bias, safety reports with amphetamine-like appetite suppressants were excluded. Disproportionality was expressed using reporting odds-ratio (ROR) and its 95% confidence interval (CI). RESULTS: Of 29 129 spontaneous reports with MPH, 23 VHD cases (7.9 per 10 000 reports) were identified, including 13 adults and 10 children. Most cases concerned injury on the mitral valve. A disproportionate reporting was observed overall (ROR 1.6, 95% CI 1.1-2.4). Analysis according to age group found that disproportionality in VHD reporting was found in adults only (ROR 2.7, 95% CI 1.6-4.7) but not in children/adolescents (ROR 1.7, 95% CI 0.9-3.2). Furthermore, amongst MPH users only, VHD reporting was higher in adults compared to children (ROR 2.7, 95% CI 1.2-6.3). CONCLUSION: VHD reporting appears rare with MPH compared to other adverse events and is increased in adults only. Our findings support a potential safety signal of VHD in adults exposed to MPH. A risk in that population cannot be excluded and requires further assessment.

Human Genetics of Semilunar Valve and Aortic Arch Anomalies.

Lesions of the semilunar valve and the aortic arch can occur either in isolation or as part of well-described clinical syndromes. The polygenic cause of calcific aortic valve disease will be discussed including the key role of NOTCH1 mutations. In addition, the complex trait of bicuspid aortic valve disease will be outlined, both in sporadic/familial cases and in the context of associated syndromes, such as Alagille, Williams, and Kabuki syndromes. Aortic arch abnormalities particularly coarctation of the aorta and interrupted aortic arch, including their association with syndromes such as Turner and 22q11 deletion, respectively, are also discussed. Finally, the genetic basis of congenital pulmonary valve stenosis is summarized, with particular note to Ras-/mitogen-activated protein kinase (Ras/MAPK) pathway syndromes and other less common associations, such as Holt-Oram syndrome.

Doenças valvares sob a perspectiva do teste cardiopulmonar de exercício: uma revisão integrativa dos últimos 10 anos / Valvular diseases from the perspective of cardiopulmonary exercise testing: an integrative review of the last 10 years

OBJETIVO: Avaliar artigos científicos sobre o uso do Teste Cardiopulmonar de Exercício (TCPE)nas valvopatias com insuficiência ou estenose moderada a grave em pacientes oligo ou assintomáticos. MÉTODOS: Trata-se de uma revisão integrativa de literatura, com artigos publicados entre 2014 e 2024, sem restrição linguística, disponíveis online na íntegra. Utilizou-se como questão norteadora: "Quais as evidências sobre a realização do teste cardiopulmonar de exercício em pacientes portadores de valvopatias moderadas a graves e assintomáticos?". A pesquisa bibliográfica foi realizadaatravés das bases de dados PUBMED/MEDLINE, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Coleção BVS, por meio dos seguintes descritores em Ciências da Saúde (DeCS): Heart Valve Diseases; Cardiopulmonry Exercise Testing, com uso do operador booleano "AND". RESULTADOS: A amostra final foi composta por 09 artigos que seguiram os critérios de inclusão e exclusão previamente definidos. CONSIDERAÇÕES Finais: O TCPE está bem estabelecido na literatura como uma opção segura, acessível e objetiva, para avaliação dos pacientes com doença valvar, permitindo análise real do condicionamento aeróbico, associado ao comportamento dos sistemas cardiovascular, pulmonar e periférico, trazendo maior precisão da avaliação clínica do paciente.

Effect of beta-blockers and angiotensin receptor blockers in reducing the aortic growth rate in children with bicuspid aortic valve-related aortopathy.

AIMS: The aim of this study is to evaluate the effect of beta-blockers and angiotensin receptor blockers in reducing the aortic growth rate in children with bicuspid aortic valve (BAV)-related aortopathy and ascending phenotype. METHODS: Consecutive paediatric patients (≤16 years) with BAV and ascending aorta (AsAo) dilation (z-score > 3) were enrolled in this observational retrospective cohort study. Patients receiving prophylactic treatment with either atenolol (0.5 to 1.0 mg/kg/daily) or losartan (0.7 to 1.4 mg/kg/daily) were compared with those who did not receive medical prophylaxis (control group). The primary outcome of interest was the annual rate of change in maximal AsAo diameter z-score in the treatment and control groups. RESULTS: From a cohort of 1005 patients, 120 (mean age 11.3 ± 4.5 years, 82% males) fulfilled the inclusion criteria and were included in the study. Patients in the treatment and control group had similar age, sex, family history of BAV, BAV morphology, and baseline AsAo diameter. During a median follow-up of 7.1 years (interquartile range 3.8-10.2), no differences were observed in the annual growth rate of aortic diameter z-score between patients on treatment and controls. The prevalence of aortic diameter progression was similar in the treatment and control groups, and treatment with atenolol or losartan was not associated with a lower rate of aortic disease progression. CONCLUSIONS: The findings revealed no significant difference in the annual aortic growth rate between treated and untreated patients. Larger cohort studies or, ideally, randomized clinical controlled trials are needed to validate these findings.

Same evidence different recommendations: a methodological assessment of transatlantic guidelines for the management of valvular heart disease.

OBJECTIVES: The aim of this study was to identify methodological variations leading to varied recommendations between the American College of Cardiology (ACC)/American Heart Association (AHA) and the European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) valvular heart disease guidelines and to suggest foundational steps towards standardizing guideline development. METHODS: An in-depth analysis was conducted to evaluate the methodologies used in developing the transatlantic guidelines for managing valvular heart disease. The evaluation was benchmarked against the standards proposed by the Institute of Medicine. RESULTS: Substantial discrepancies were noted in the methodologies utilized in development processes, including Writing Committee composition, evidence evaluation, conflict of interest management and voting processes. Furthermore, despite their mutual differences, both methodologies demonstrate notable deviations from the Institute of Medicine standards in several essential areas, including literature review and evidence grading. These dual variances likely influenced divergent treatment recommendations. For example, the ESC/EACTS recommends transcatheter edge-to-edge repair for patients with chronic severe mitral regurgitation ineligible for mitral valve surgery, while the ACC/AHA recommends transcatheter edge-to-edge repair based on anatomy, regardless of surgical risk. ESC/EACTS guidelines recommend a mechanical aortic prosthesis for patients under 60, while ACC/AHA guidelines recommend it for patients under 50. Notably, the ACC/AHA and ESC/EACTS guidelines have differing age cut-offs for surgical over transcatheter aortic valve replacement (<65 and <75 years, respectively). CONCLUSIONS: Variations in methodologies for developing clinical practice guidelines have resulted in different treatment recommendations that may significantly impact global practice patterns. Standardization of essential processes is vital to increase the uniformity and credibility of clinical practice guidelines, ultimately improving healthcare quality, reducing variability and enhancing trust in modern medicine.

Can resistance prehabilitation training bring additional benefits in valvular cardiac surgery? protocol for a randomized controlled trial.

INTRODUCTION: Cardiovascular diseases (CVD) are a group of illnesses that include coronary heart disease, cerebrovascular disease, congenital heart disease and deep vein thrombosis. Major surgery is often chosen as the treatment of choice for CVD. The concept of fast-track rehabilitation after surgery appeared in the 1970s. Participation in these exercise-based prehabilitation programmes may decrease postoperative complications and length of hospital stay. The primary aim of the present study is to evaluate whether the implementation of an additional resistance training (RT) prehabilitation protocol within cardiac exercises based prehabilitation can reduce intensive care unit (ICU) length of stay, postoperative complications and hospital length of stay (LOS). METHODS: A protocol of a prospective, parallel, randomised clinical trial includes 96 adult patients diagnosed with valvular pathology and who have been scheduled for surgery. The participants will be randomly assigned to two groups of 48. Control group will be treated with ventilatory and strengthening of respiratory muscles, and aerobic exercise. Experimental group, in addition, will be treated with RT of peripheral muscles. Both hospital stay and ICU stay will be assessed as main variables. Other secondary variables such as exercise capacity, quality of life and respiratory values will also be assessed. Quantitative variables will be analysed with a T-Test or ANOVA, or Mann Witney if the distribution is non-parametric. RESULTS AND CONCLUSION: This will be the first controlled clinical study focused on adding strength exercise as an additional treatment during prehabilitation. The results of this study will focus on helping to improve rehabilitation and prehabilitation protocols, considering that it is essential to maintain pulmonary training, as well as the inclusion of peripheral exercises that help people with heart disease to be in a better physical condition in order to increase their participation and sense of quality of life.

Association of Matrix Metalloproteinase-2 (MMP-2) and MMP-9 Promoter Variants, Their Serum Levels, and Activities with Aortic Valve Calcification (AVC) in a Population from Western Iran.

Background: Matrix metalloproteinase (MMP) enzyme gene polymorphisms MMP-2-1575G/A and MMP-9-1562C/T promoter polymorphism, their serum levels, and activity are associated with aortic valve calcification (AVC). Materials and Methods: The synergistic link between the risk of AVC and the alleles T and A of MMP-9 and MMP-2 was investigated, respectively. Ninety-two cases with AVC and 92 healthy individuals from the west of Iran were included, and MMP- 2-1575G/A and MMP-9-1562C/T promoter polymorphisms were detected using PCR-RFLP. The serum levels and activity of MMP-2 and -9 were assessed using ELISA and gelatin zymography methods, respectively. In addition, serum biochemical markers, including FBS, urea and creatinine, cholesterol, triglyceride, HDL, LDL, calcium, phosphorus, and blood pressure: systolic blood pressure and diastolic blood pressure were measured. Results: Heart valve calcification disease was associated with a comparatively higher frequency of the A allele of the MMP2-1575 variation (p = 0.002). In addition, the frequency of T allele of the MMP9-1562 variant was higher than the control group (p = 0.007). Conclusion: MMP-2 and MMP-9 serum levels and activities were observed to be considerably higher in the experimental group than in the control group (p < 0.001). Patients are more susceptible to cardiovascular disease than the control group due to elevated serum levels and activity of MMP-2 and MMP-9.

Comprehensive clinical application analysis of artificial intelligence-enabled electrocardiograms for screening multiple valvular heart diseases.

BACKGROUND: Valvular heart disease (VHD) is becoming increasingly important to manage the risk of future complications. Electrocardiographic (ECG) changes may be related to multiple VHDs, and (AI)-enabled ECG has been able to detect some VHDs. We aimed to develop five deep learning models (DLMs) to identify aortic stenosis, aortic regurgitation, pulmonary regurgitation, tricuspid regurgitation, and mitral regurgitation. METHODS: Between 2010 and 2021, 77,047 patients with echocardiography and 12-lead ECG performed within 7 days were identified from an academic medical center to provide DLM development (122,728 ECGs), and internal validation (7,637 ECGs). Additional 11,800 patients from a community hospital were identified to external validation. The ECGs were classified as with or without moderate-to-severe VHDs according to transthoracic echocardiography (TTE) records, and we also collected the other echocardiographic data and follow-up TTE records to identify new-onset valvular heart diseases. RESULTS: AI-ECG adjusted for age and sex achieved areas under the curves (AUCs) of >0.84, >0.80, >0.77, >0.83, and >0.81 for detecting aortic stenosis, aortic regurgitation, pulmonary regurgitation, tricuspid regurgitation, and mitral regurgitation, respectively. Since predictions of each DLM shared similar components of ECG rhythms, the positive findings of each DLM were highly correlated with other valvular heart diseases. Of note, a total of 37.5-51.7% of false-positive predictions had at least one significant echocardiographic finding, which may lead to a significantly higher risk of future moderate-to-severe VHDs in patients with initially minimal-to-mild VHDs. CONCLUSION: AI-ECG may be used as a large-scale screening tool for detecting VHDs and a basis to undergo an echocardiography.

Impact of valvular surgery according to frailty risk in patients with infective endocarditis.

BACKGROUND: Observational studies suggest that valvular surgery can reduce mortality in selected patients with infective endocarditis (IE). However, the benefit of this intervention according to frailty levels remains unclear. Our study aims to assess the effect of valvular surgery according to frailty status in this population. METHODS: We performed a retrospective study using the 2016-2019 National Inpatient Sample database. Adult patients with a primary diagnosis of IE were included. Frailty was assessed using the Hospital Frailty Risk Score. Inverse probability of treatment weighting (IPTW) was used to balance baseline differences between groups. RESULTS: A total of 53,275 patients with IE were included, with 18.3% underwent valvular surgery. The median age was 52 (34-68) years, with 41% females. Overall, 42.7% had low risk of frailty, 53.1% intermediate risk, and 4.2% high risk. After IPTW adjustment, in-hospital mortality was similar both for the entire cohort between valvular and non-valvular surgery groups (3.7% vs. 4.1%, p = .483), and low (1% vs. 0.9%, p = .952) or moderate (5.4% vs. 6%, p = .548) risk of frailty. However, patients at high risk of frailty had significantly lower in-hospital mortality in the valvular surgery group (4.6% vs. 13.9%, p = .016). Renal replacement therapy was similar between groups across frailty status. In contrast, surgery was associated with increased use of mechanical circulatory support and pacemaker implantation. CONCLUSIONS: Our findings suggest that there was no difference in survival between valve surgery and medical management in patients at low/intermediate frailty risk, but not for high-risk individuals.

Atorvastatin Effect on Aortic Dilatation and Valvular Calcification Progression in Bicuspid Aortic Valve (BICATOR): A Randomized Clinical Trial.

BACKGROUND: Ascending aorta dilation and aortic valve degeneration are common complications in patients with bicuspid aortic valve. Several retrospective studies have suggested the benefit of statins in reducing these complications. This study aimed to determine whether atorvastatin treatment is effective in reducing the growth of aortic diameters in bicuspid aortic valve and if it slows the progression of valve calcification. METHODS: In a randomized clinical trial, 220 patients with bicuspid aortic valve (43 women; 46±13 years of age) were included and treated with either 20 mg of atorvastatin per day or placebo for 3 years. Inclusion criteria were ≥18 years of age, nonsevere valvular dysfunction, nonsevere valve calcification, and ascending aorta diameter ≤50 mm. Computed tomography and echocardiography studies were performed at baseline and after 3 years of treatment. RESULTS: During follow-up, 28 patients (12.7%) discontinued medical treatment (15 on atorvastatin and 13 taking placebo). Thus, 192 patients completed the 36 months of treatment. Low-density lipoprotein cholesterol levels decreased significantly in the atorvastatin group (median [interquartile range], -30 mg/dL [-51.65 to -1.75 mg/dL] versus 6 mg/dL [-4, 22.5 mg/dL]; P<0.001). The maximum ascending aorta diameter increased with no differences between groups: 0.65 mm (95% CI, 0.45-0.85) in the atorvastatin group and 0.74 mm (95% CI, 0.45-1.04) in the placebo group (P=0.613). Similarly, no significant differences were found for the progression of the aortic valve calcium score (P=0.167) or valvular dysfunction. CONCLUSIONS: Among patients with bicuspid aortic valve without severe valvular dysfunction, atorvastatin treatment was not effective in reducing the progression of ascending aorta dilation and aortic valve calcification during 3 years of treatment despite a significant reduction in low-density lipoprotein cholesterol levels. REGISTRATION: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001808-57. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02679261.

Lack of awareness of secondary rheumatic prevention in preoperative candidates for mitral valve surgery - alarming situation.

BACKGROUND: We conducted this study to assess the compliance with secondary rheumatic prophylaxis among preoperative patients with rheumatic mitral valve disease undergoing valvular heart surgery at a tertiary care cardiac hospital in a developing country. METHODS: This is a descriptive cross-sectional study conducted at a tertiary care cardiac hospital in Karachi, Pakistan. The inclusion criteria encompassed patients of any sex, aged between 18 and 80 years, who had been diagnosed with rheumatic mitral valve disease through transthoracic echocardiography and had undergone valvular heart surgery. The level of compliance with secondary rheumatic prophylaxis and barriers toward noncompliance was assessed during routine preoperative interview session. This preventive measure plays a crucial role in reducing the progression of the disease and improving patient outcomes. RESULTS: Out of the 239 patients included in the study, 125 (52.3%) were females, with a mean age of 38.8 ± 11.8 years. The majority of patients (88.7%) came from rural areas. Among the patients, 79 (33.1%) received rheumatic prophylaxis, while 160 (66.9%) did not adhere to it regularly. The common barriers for receiving rheumatic prophylaxis were non availability (41.0%) and nonaffordability (40.6%). Additionally, 28.0% of patients had lacked awareness of the importance of rheumatic prophylaxis, and 2.5% expressed fear of injection site pain and subsequent symptoms. CONCLUSIONS: A concerning level of noncompliance with secondary rheumatic prophylaxis was observed. The barriers identified in patients who did not receive rheumatic prophylaxis were primarily related to affordability, availability, lack of awareness, and fear of injection site pain and subsequent symptoms.

The hybrid (physical-computational) cardiovascular simulator to study valvular diseases.

To better understand the impact of valvular heart disease (VHD) on the hemodynamics of the circulatory system, investigations can be carried out using a model of the cardiovascular system. In this study, a previously developed hybrid (hydro-numerical) simulator of the cardiovascular system (HCS) was adapted and used. In our HCS Björk-Shiley mechanical heart valves were used, playing the role of mitral and aortic ones. In order to simulate aortic stenosis (AS) and mitral regurgitation (MR), special mechanical devices have been developed and integrated with the HCS. The simulation results proved that the system works correctly. Namely, in the case of AS - the mean pulmonary arterial pressure was increased due to increased preload of the left ventricle and the decrease in right ventricular preload was caused by a decrease in systemic arterial pressure. The severity of AS was performed based on the transaortic pressure gradient as well as using the Gorlin and Aaslid equations. In the case of severe AS, when the mean gradient was above 40 mmHg, the aortic valve orifice area was 0.5 cm2, which is in line with ACC/AHA guidelines. For the case of MR - with increasing severity of MR, there was a decrease in the left ventricular pressure and an increase in left atrial pressure. Using mechanical heart valves to simulate VHD by the HCS can be a valuable tool for biomedical research, providing a safe and controlled environment to study and understand the pathophysiology of VHD.

Decellularization and characterization of camel pericardium as a new scaffold for tissue engineering and regenerative medicine.

BACKGROUND: Valvular heart diseases (VHDs) have become prevalent in populations due to aging. Application of different biomaterials for cardiac valve regeneration and repair holds a great promise for treatment of VHD. Aortic valve replacement using tissue-engineered xenografts is a considered approach, and the pericardium of different species such as porcine and bovine has been studied over the last few years. It has been suggested that the animal origin can affect the outcomes of replacement. METHODS: So, herein, we at first decellularized and characterized the camel pericardium (dCP), then characterized dCP with H&E staining, in vitro and in vivo biocompatibility and mechanical tests and compared it with decellularized bovine pericardium (dBP), to describe the potency of dCP as a new xenograft and bio scaffold. RESULTS: The histological assays indicated less decluttering and extracellular matrix damage in dCP after decellularization compared to the dBP also dCP had higher Young Modulus (105.11), and yield stress (1.57 ± 0.45). We observed more blood vessels and also less inflammatory cells in the dCP sections after implantation. CONCLUSIONS: In conclusion, the results of this study showed that the dCP has good capabilities not only for use in VHD treatment but also for other applications in tissue engineering and regenerative medicine.

Iron parameters analysis in dogs with myxomatous mitral valve disease.

BACKGROUND: Myxomatous mitral valve disease (MMVD) is the most common acquired cardiovascular disease in small breed dogs. In contrast to human patients with heart failure (HF), iron deficiency (ID) prevalence in dogs with MMVD is weakly known. The study aimed to assess the usability of ID markers in serum and reticulocyte parameters from whole blood of dogs with MMVD to evaluate early ID symptoms. RESULTS: Sixty-eight dogs (43 male and 25 female) were included in the study. MMVD dogs were assigned according to the 2019 ACVIM guidelines for groups B1 (n = 9), B2 (n = 10), C (n = 27) and D (n = 10). Groups were also combined into B1 and B2 as non-symptomatic HF and C with D as symptomatic HF. Healthy controls were 12 dogs. Serum iron concentration below the reference range in dogs with MMVD was 12.5%. Other ID indices, such as %SAT, UIBC, and TIBC were similar in the MMVD groups and healthy controls (p > 0.05 for all parameters). Statistical comparison between control group and 4 groups of different stages of MMVD showed that significant differences occur only in serum transferrin. The assessment of ferritin and soluble transferrin receptors using Western Blotting did not show differences between control (n = 7) and MMVD (n = 33) dogs. Study has shown positive correlation between ID parameters and echocardiographic indices such as LA/Ao and LVIDdN, and some biochemical parameters. A significant increase in reticulocytes percentage, assessed manually, was observed in the HF group of animals (p = 0.027) compared to the control group. CONCLUSIONS: Studies have shown that ID parameters in serum are not significantly different in dogs with MMVD compared to healthy dogs. However, there is a clear correlation between atrial size and normalised left ventricular size to body size and some biochemical parameters, including ID parameters and therefore the severity of MMVD.