Impact of Microvascular Obstruction on the Assessment of Coronary Flow Reserve,Index of Microcirculatory Resistance,and Fractional Flow Reserve After ST-Segment Elevation Myocardial Infarction

Background

Invasive assessment of coronary physiology (IACP) offers important prognostic insights in ST-segment elevation myocardial infarction (STEMI) but the dynamics of coronary recovery are poorly understood.

Objectives

This study sought to examine the evolution of coronary flow reserve (CFR), index of microcirculatory resistance (IMR), ratio of distal coronary pressure (Pd) to mean aortic pressure (Pa), and fractional flow reserve (FFR) in patients undergoing primary percutaneous coronary intervention (PPCI).

Methods

82 patients with STEMI underwent IACP at PPCI. Repeat IACP was performed in 61 patients (74%) at day 1 and in 46 patients (56%) at 6 months. Contrast-enhanced cardiac magnetic resonance imaging (CMR) was performed in 45 patients (55%) at day 1 and in 41 patients (50%) at 6 months. Changes in IACP were compared between patients with and without microvascular obstruction (MVO) on CMR.

Results

MVO was present in 21 of 45 patients (47%). Patients with MVO had lower CFR at PPCI and day 1 (p < 0.05) and a trend toward higher IMR values (p = 0.07). At 6 months, CFR and IMR were not significantly different between the groups. Baseline flow and Pd/Pa remained stable over time but FFR reduced significantly between PPCI and 6 months (p = 0.008); this reduction was mainly observed in patients with MVO (p = 0.006) but not in those without MVO (p = 0.21).

Conclusions

In PPCI-treated patients with STEMI, coronary microcirculation begins to recover within 24 h and recovery progresses further by 6 months. FFR significantly reduces from baseline to 6 months. The presence of MVO indicates a highly dysfunctional microcirculation.     

Iron-dependent erythropoiesis in women with excessive menstrual blood losses and women with normal menses

In women of fertile age, iron loss consequent to excessive menstrual discharge is by far the most frequent cause of iron-deficient anemia. However, the relationship between menstrual discharge and iron loss is poorly understood. In this prospective study, total menstrual and iron losses were assayed in a large cohort of non-anemic women and women with excessive menstrual blood losses (menorrhagia) in order to provide data useful for intervention. One hundred and five Caucasian women aged 20–45 years were recruited. Blood cell count and serum ferritin (SF) levels were determined in each case before menses. Menstrual fluid losses (MFL) were determined using a standardized pads’ weight method. Hematin concentration was assayed by a variant of the Alkaline Hematin Method from which iron concentration was calculated. Mean SF levels were 36.2 (range 8.6–100) ng/ml in healthy women and 6.4 (range 5–14) ng/ml in patients with menorrhagia. Median values of iron lost/cycle were 0.87 mg in healthy women and 5.2 mg in patients with menorrhagia (ranges 0.102–2.569 and 1.634–8.665 mg, respectively, p?<?0.001). In women with menorrhagia, iron lost/cycle strongly correlated (0.789, p?<?0.001) with MFL. In conclusion, healthy women with normal menses lose, on average, 1 mg iron/cycle. Average iron losses in patients with menorrhagia are, at least in our cohort, on average, five-to-six times higher than normal. Most women with menorrhagia had totally depleted iron stores. Indirect, quantitative evaluation of iron lost with menses may be useful to assess the risk of developing iron-deficient anemia in individual patients.     

Relationship between the 46/1 haplotype of the JAK2 gene and the JAK2 mutational status and allele burden,the initial findings,and the survival of patients with myelofibrosis

An association has been reported between a specific haplotype of the JAK2 gene, the homozygous 46/1 haplotype, and a predisposition to the development of chromosome Philadelphia-negative myeloproliferative neoplasms. Concerning myelofibrosis (MF), controversy remains on the relationship between the above JAK2 haplotype and the patients’ clinicohematological features and survival. Among 132 patients with MF (60 % primary MF, 20 % postpolycythemia vera MF, 20 % post-essential thrombocythemia MF; 59 % JAK2V617F positive) who were analyzed for the JAK2 46/1 haplotype, 29 were found to be homozygous and 53 heterozygous. The homozygous 46/1 haplotype was more often observed in JAK2V617F-positive patients (29.5 versus 11 %, p?=?0.012). Moreover, among JAK2V617F-positive patients, those who were homozygous for the 46/1 haplotype had a higher allele burden than the remainder (92 versus 48 %, p?=?0.0017). Overall, patients with homozygous 46/1 haplotype showed significantly higher hemoglobin values and higher leukocyte counts, but no association was seen with other clinicohematological features. Finally, no relationship was observed between the JAK2 46/1 haplotype and either the patients’ prognostic score or survival.