Prevention of neointimal proliferation by immunosuppression in synthetic vascular grafts

OBJECTIVE

Immunosuppressive agents have been proposed to reduce neointimal hyperplasia in synthetic vascular grafts. Thus, the purpose of the present study was to evaluate the safety and efficacy of rapamycins (systemic vs. local vs. oral administration) and mycophenolate mofetil (MMF) to reduce intimal hyperplasia in infrarenal synthetic vascular grafts of the rat.

METHODS

Fifty-four Wistar rats (250 g) completed the study after a synthetic vascular graft (ePTFE, Gore-tex, 2 mm diameter, 10 mm length) was implanted end-to-end in the infrarenal aorta. The animals were divided into three groups: group 1 consisted of 12 control animals, group 2 consisted of 37 rats receiving rapamycins, either per os (RAD, 1.5 or 3 mg/kg), intraperitoneally (RPM, 1.5 or 3 mg/kg) or locally (RPM soaking of the graft); and in group 3 (n=5), MMF (40 mg/kg) was administered orally. The animals were followed weekly with weight controls and signs of toxicity for 30 (n=37) and 60 (n=17) days, respectively. All animals were sacrificed and underwent histological examination at completion of the study.

RESULTS

All animals survived in groups 1 and 3, but five died in group 2. The weight gain was normal in all groups, except for the subgroup 2a receiving high dose rapamycins orally. All rats in group 3 suffered from diarrhea, whereas animals receiving high dose rapamycins showed toxic signs (hair loss, wound healing problems). Histological examination showed a significant increase in intimal hyperplasia in group 1 (0.03+/-0.01 and 0.14+/-0.05 microm after 30 and 60 days, respectively; P<0.01). Rapamycins in either application or dosage had no significant effect on intimal hyperplasia.

CONCLUSIONS

Local or systemic administration of rapamycins has no effect on intimal hyperplasia in synthetic vascular grafts. In contrast, toxic signs with weight loss were observed in animals treated with high dose rapamycins, but not in those treated with MMF. Thus, in the rat model, immunosuppression with rapamycins or MMF cannot be recommended for the prevention of intimal hyperplasia in the synthetic vascular graft model.

Prognostic value of visual and quantitative CMR regional myocardial function in patients with suspected myocarditis

According to updated Lake-Louise Criteria, impaired regional myocardial function serves as a supportive criterion in diagnosing myocarditis. This study aimed to assess visual regional wall motional abnormalities (RWMA) and novel quantitative regional longitudinal peak strain (RLS) for risk stratification in the clinical setting of myocarditis. In patients undergoing CMR and meeting clinical criteria for suspected myocarditis global longitudinal strain (GLS), late gadolinium enhancement (LGE), RWMA and RLS were assessed in the anterior, septal, inferior, and lateral regions and correlated to the occurrence of major adverse cardiac events (MACE), including heart failure hospitalization, sustained ventricular tachycardia, recurrent myocarditis, and all-cause death. In 690 consecutive patients (age: 48.0 ± 16.0 years; 37.7% female) with suspected myocarditis impaired RLS was correlated with RWMA and LV-GLS but not with the presence of LGE. At median follow up of 3.8 years, MACE occurred in 116 (16.8%) patients. Both, RWMA and RLS in anterior-, septal-, inferior-, and lateral- locations were univariately associated with outcomes (all p < 0.001), but not after adjusting for clinical characteristics and LV-GLS. In the subgroup of patients with normal LV function, RWMA were not predictive of outcomes, whereas septal RLS had incremental and independent prognostic value over clinical characteristics (HRadjusted = 1.132, 95% CI 1.020-1.256; p = 0.020). RWMA and RLS can be used to assess regional impairment of myocardial function in myocarditis but are of limited prognostic value in the overall population. However, in the subgroup of patients with normal LV function, septal RLS represents a distinctive marker of regional LV dysfunction, offering potential for risk-stratification.

Sports behaviour and adherence to sports and exercise recommendations in patients with myocarditis

Aim

In the clinical setting of acute myocarditis, existing guidelines recommend refraining from moderate-intensity to high-intensity sports for 3-6 months, yet the extent to which these recommendations are implemented by clinicians and followed by patients remains unclear.

Methods

From January 2020 to December 2023, consecutive patients with myocarditis according to European Society of Cardiology criteria were prospectively enrolled. Myocarditis was categorised into acute, subacute and non-acute myocarditis. Patients completed a sports questionnaire and sports behaviour was categorised into no sports (NSP), recreational (REC) or competitive sports (COMP).

Results

A total of 165 patients with myocarditis (mean age 50±17 years, 35% women) completed the questionnaire. Overall 73 (44%) patients received sports counselling. A total of 44 (72%) patients engaged in sports (REC+COMP) with acute or subacute myocarditis, received sports counselling with 38 (87%) adhering. Overall COMP patients (all male) received more counselling (11/11; 100%) compared with REC (53/105; 50%) and NSP (9/49; 18%). Of 39 women in the REC group, 14 (36%) received recommendations, whereas of 66 men 39 (59%) received recommendations (p<0.001). Of all patients engaged in sports, 55% received recommendations. Self-reported adherence to recommendations was significantly lower in COMP (73%) compared with REC (92%, p<0.001).

Conclusion

Although only half of the myocarditis patients received counselling regarding sports activity, adherence to these recommendations was generally high but varied by activity level. Women received fewer recommendations overall compared with men. While competitive athletes were counselled more frequently than recreational athletes, they were less likely to adhere to the recommendations.

Sex- specific differences in suspected myocarditis presentations and outcomes

BACKGROUND

Signs and symptoms of myocarditis may vary among men and women.

OBJECTIVES

This study aimed to analyze sex-specific differences in the presentation and outcomes of patients with suspected myocarditis.

METHODS

Patients meeting clinical ESC criteria for suspected myocarditis were included from two tertiary centers between 2002 and 2021. Baseline characteristics, cardiac magnetic resonance (CMR), and outcomes (i.e. major adverse cardiovascular events (MACE), including all-cause death, ventricular tachycardia, hospitalization for heart failure, and recurrent myocarditis) in women and men were compared.

RESULTS

776 consecutive patients (mean age 48 ± 16 years, 286 [36.9 %] women) were followed for a median of 3.7 years. Compared to men, women presented more often with severe dyspnea (NYHA III-IV: 25.9 % versus 19.2 % of men; p = 0.029), while chest pain was more frequent in men (39.8 % versus 32.2 % in women; p = 0.037). There was no difference in left ventricular ejection fraction at the time of presentation (women: 48.5 ± 15.4 % versus men: 48.6 ± 15.1 %;p = 0.954). Further, no sex-specific difference in the occurrence of MACE was noted; however, women were more often hospitalized for heart failure than men (women: 9.8 % versus men: 5.3 %, p = 0.018). Accordingly, female sex was independently associated with heart failure hospitalization in an adjusted model (HR: 2.31, 95 % CI:1.25-4.26; p = 0.007). The prognostic value of CMR markers was similar in both sex.

CONCLUSION

Significant sex-specific differences in presentations and imaging findings are found in patients with suspected myocarditis. Female sex is associated with a twofold increase in the risk of heart failure hospitalization, which should be considered in risk stratification.