Diagnostic and prognostic contribution of DPD scintigraphy in transthyretin V30M cardiac amyloidosis

BACKGROUND

Early diagnosis and prognostic stratification of cardiac transthyretin amyloidosis are crucial. Although 99mTc 3,3-diphosphono-1,2-propanedicarboxylic acid (DPD) scintigraphy is the preferred method for the non-invasive diagnosis, its accuracy appears to be limited in transthyretin amyloidosis protein (ATTR) V30M mutation. Furthermore, its prognostic value in this mutation is unknown. This study investigated the diagnostic value of DPD scintigraphy to detect ATTR cardiomyopathy in V30M mutation and explored its prognostic value regarding mortality.

METHODS

A total of 288 ATTR V30M mutation carriers (median age: 46 years; 49% males) without myocardial thickening (defined as septal thickness ≥13mm) attributable to other causes and who underwent DPD scintigraphy were enrolled. ATTR cardiomyopathy was defined by septal thickness ≥13mm and at least one of the criteria: late heart-to-mediastinum (H/M) 123I-metaiodobenzylguanidine (MIBG) uptake ratio <1.60; electrical heart disease or biopsy-documented amyloidosis.

RESULTS

ATTR cardiomyopathy was identified in 41 (14.2%) patients and cardiac DPD uptake in 34 (11.8%). During a mean follow-up of 33.6 ± 1.2 months, 16 patients died (5.6%). Mortality was 14 times higher in patients with ATTR cardiomyopathy, 13 times higher in those with DPD uptake and 10 times higher in those with late H/M MIBG <1.60. The combined assessment of septal thickness and cardiac DPD uptake improved risk stratification: patients without septal thickening and without DPD retention had an excellent prognosis while those who presented either or both of them had a significantly worse prognosis, with 5-year mortality rates ranging from 39.9 to 53.3%.

CONCLUSIONS

DPD scintigraphy is useful for prognostic stratification of ATTR V30M mutation carriers. Patients without septal thickening and no DPD uptake present the best prognosis compared to those with any signs of cardiac involvement.

Acute coronay syndrome in a patient with severe hemophilia A: Dificult decisions

Hemophilia A is an inherited coagulation disease characterized by factor VIII (FVIII) deficiency and is associated with high hemorrhagic risk, especially in its severe forms. As the average life expectancy of patients with hemophilia has increased, so has the prevalence of acute coronary events. There is however limited experience in dealing with them. The strategy of acting on acute coronary events in patients with hemophilia, as demonstrated in the present case, is a real challenge, not only due to the need for antiplatelet therapy (which is essential in the prevention of stent thrombosis, but increases hemorrhagic risk), but also due to the lack of specific recommendations related to the most adequate and safe replacement therapy in these situations. The authors describe the case of a 48-year-old man with unstable angina and a previous diagnosis of severe hemophilia A who underwent percutaneous coronary intervention under FVIII therapy without hemorrhagic complications.

The sensitivity of DPD scintigraphy to detect transthyretin cardiac amyloidosis in V30M mutation depends on the phenotypic expression of the disease

Background: There is a growing need for a non-invasive test to detect cardiac involvement in patients with transthyretin-related hereditary amyloidosis (ATTR) caused by V30M mutation. ^99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy is a promising method, but its accuracy in this particular mutation remains unknown.Methods: A cohort of 179 patients: 92 with early-onset disease (EoD, symptoms <50-years-old), 33 with late-onset disease (LoD) and 54 asymptomatic carriers were prospectively evaluated and underwent DPD scintigraphy, which was compared with the results of echocardiogram, ambulatory blood pressure monitoring, 24 h-Holter, myocardial ¹²³I-metaiodobenzylguanidine imaging and NT-proBNP.Results: Amyloid cardiomyopathy, defined as septal thickness ≥13 mm, was present in 32 patients (17.9%) and was more frequent in those with LoD (OR: 3.68, p = .003). Cardiac DPD uptake was present in 22 individuals (12.3%) and correlated with parameters indicative of cardiac amyloidosis. DPD imaging was strongly influenced by the age of disease onset: among patients with myocardial thickening, cardiac DPD retention was present in 11/15 (73.3%) with LoD, in contrast to only 4/17 (26.7%) with EoD (p = .005). Two patients with myocardial thickening and normal DPD scintigraphy underwent endomyocardial biopsy that confirmed ATTR amyloidosis.Conclusion: DPD scintigraphy presents suboptimal sensitivity to detect cardiac involvement in ATTRV30M, particularly in symptomatic patients with EoD.

P3808iBox-CRT: Better response, less complicated, equally fast

Introduction

The optimization of the left ventricle (LV) pacing site guided by the electrical delay increases CRT response rate (RR), however it's necessary to develop technology that allows its universal use.

Purpose

The aim is automatically, and operator-independent, access the conduction delay between the right ventricular (RV) stimulus and the LV available veins in order to select the LV pacing site. It is further intended to compare the total procedure and radiation times in relation to an historical control group.

Methods

Prospective, single-center study that included patients undergoing CRT implant according to the current ESC Guidelines. All patients were submitted to a clinical, electrocardiographic and echocardiographic basal evaluation prior to CRT implantation and at 6 months of follow-up.

To evaluate conduction delays between the RV lead and the LV available veins (RV-LV delay), an external interface - intelligent Box for CRT (iBox-CRT) was used. Four measurements in at least two different tributary veins were made. The implant of all the LV leads was guided by the longest measured delay.

A positive response to CRT was defined as an improvement of >10% in left ventricle ejection fraction (LVEF) or a reduction of end-systolic volume (ESV)>15%. The results were compared to a control group (CG) of pts submitted to CRT implantation in the conventional way.

Results

60 patients were included (68.3% males, 38% ischemic, mean age 67.4±10.2 years) and submitted to CRT implant (37 CRT-P; 23 CRT-D). At basal evaluation, LVEF was 28±7%, end-diastolic volume (EDV) was 200±73ml and ESV 145±64ml. CG (n=51) had similar characteristics.

The RR was 85.7%, significantly higher compared to the CG (55.9%, p=0.003). The ESV reduced 38.2±3% in responders vs 5.7±2% in non-responders (NR) (p=0,005), EDV reduced 33.3±16% in responders vs 13.6±10% in NR (p=0.002), the mean LVEF improved 11% in responders vs −1% in NR (p=0.02).

At follow-up, the mean ESV in the study group (SG) was 89±44 ml vs 132±75ml in the CG (p=0.002) and the EDV 136±51 vs 190±78 (p=0.007).

In addition to a much better response rate, the responders in the study group had significantly higher mean LVEF at follow-up (39±11% vs 37±7%, p=0.032).

The mean intra-procedure RV-LV delay was 187±34mseg. In the responder group the baseline delay was usually higher (190±35 msec) vs NR group RV-LV delay (165±23 msec; p=NS).

Compared with CG, the automatic assessment of RV-LV delay with iBox-CRT did not increase fluoroscopy time (15±16min vs 18±16; p=NS) and shortened procedure time (65±34 vs 108±83min, p<0.005).

Conclusions

The iBox-CRT use enabled an automatic and operator independent RV-LV delays measurement, in order to implant the LV lead at the most delayed site. This technique translated into a major increase in CTR response rate, not compromising the procedure duration nor increasing the radiation exposure.