[Treatment of an uncommon case of a cardiogenic shock : Simultaneous use of a VA-ECMO and an Impella-CP®]

We report the case of a 48-year old woman where probably the intramuscular administration of glucocorticoids by an orthopedist induced a pheochromocytoma crisis. The development of a cardiogenic shock with a cardiac arrest made the use of a venoarterial extra corporeal membrane oxygenation (VA-ECMO, Cardiohelp®, Maquet, Rastatt) necessary. To treat a pulmonary edema under VA-ECMO an Impella-CP® (Abiomed, Aachen) was implanted. A coronary angiography, endomyocardial biopsies and a computer tomography were performed. Finally a 7 cm × 5 cm tumor mass in the left adrenal medulla was detected. The blood values presented high levels of catecholamines. The total results of the examinations led us to the final diagnosis of a pheochromocytoma which was finally surgical removed.

[Myocardial perfusion scintigraphy 2008 in Germany - results of the fourth query]

AIM

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society herewith present the results of the 4th survey on myocardial perfusion scintigraphy (MPS) of the year 2008.

METHOD

310 questionnaires (191 private practices (PP), 93 hospitals (HO), 31 university hospitals (UH)) were evaluated.

RESULTS

MPS of 98947 patients were reported. 15% of them were younger than 50 y, 57% between 50 and 70 y and 28% older than 70 y. 88% [2007: 83%] of all were studied with Tc-99m perfusion tracers. The patient radiation exposure of a stress and rest protocol considering German standard recommended doses was 8.5 mSv, of a stress-only protocol 1.9 mSv. 77% [2007: 76%] of the MPS were performed in PP, 15% [2007: 15%] in HO and 8% [2007: 9%] in UH. From 2005 to 2008 there was a mild increase in the MPS numbers by 1.2% (PP +7.1%, HO -5.5%, UH -31.4%). The type of stress was pharmacological in 30% [2007: 27%]; 68% adenosine (of these 22% with exercise), 29% dipyridamole (of these 64% with exercise), and <1% dobutamine. Gated SPECT was performed in 46% [2007: 47%] of all rest and in 42% [2007: 44%] of all stress MPS. 62% [2007: 61%] of all institutions did not use perfusion scores.

CONCLUSION

The MPS numbers from 2005 to 2008 in Germany can be regarded as stable. However, there are considerable shifts from HO and UH to PP. The well known potential of MPS considering risk stratification and functional analysis has not been tapped so far. Both gated SPECT and a quantitative perfusion analysis should be performed routinely in every patient.

[Myocardial perfusion scintigraphy 2006 in Germany. Results of the query and current status]

AIM

This second survey was to deliver further information on myocardial perfusion scintigraphy (MPS) in Germany in 2006.

METHOD

351 questionnaires were evaluated: 207 private practices (PP), 117 hospitals (HO), 27 from university hospitals (UH).

RESULTS

MPS of 106 331 patients were reported, 85% were investigated with (99m)Tc-perfusion tracers. 74% [2005 = 72%] were performed in PP, 17% [2005 = 15%] in HO and 9% [2005 = 13%] in UH. PP, which participated in 2005 and 2006, demonstrated an increase by 3,9% (HO 0%, UH - 13,0%). The type of stress was pharmacological in 27% [2005 = 22%]; 54% adenosine (of these 29% with exercise), 37% dipyridamole (of these 56% with exercise), and 9% dobutamine. Gated SPECT was performed in 42% [2005 = 36%] of all rest- and in 39% [2005 = 32%] of all stress MPS. An attenuation correction was used by 69 [2005 = 78] institutions. 40% of all MPS were performed in patients suspected to have CAD. 24% of all institutions reported changes in the use of MPS by competing methods.

CONCLUSION

There is a small increase of MPS between 2005 and 2006 despite competing methods. Gated SPECT has experienced more acceptance. Suspicion of CAD is an important indication of MPS. In order to tap the full potential of MPS a gated SPECT should be performed routinely.

Left anterior descending coronary artery: long-term angiographic results of CABG with endarterectomy

AIM

The procedure of coronary bypass grafting (CABG) with coronary endarterectomy (CE) is controversial. However, in the setting of severely calcified coronary arteries CE may enable complete revascularization. Complete revascularization, especially of the left anterior descending artery (LAD), is important for long-term outcome. In this study we assessed long-term LAD graft patency and anterior wall function after CABG with CE of the LAD.

METHODS

Between 1984 and 1992, 283 patients underwent CABG with CE of the LAD. In 50 patients (47 men), aged 59+/-7.6 (40-77), clinical reassessment and surveillance angiography were performed. In all patients complete revascularization had been achieved with 3.5+/-1 (1-5) grafts/patient with 1-3 CE/patient. The LAD was grafted either with a saphenous vein segment (N=38) or with left intern thoracic artery (N=12). A graft obstructed less than 50% in diameter was defined as patent.

RESULTS

At follow-up 39 patients (78%) were in CCS class I/II and had improved significantly (P<0.000). Control angiography after 7.6+/-2.5 (3.5-11.7) years after CABG revealed a patent LAD graft in 30/50 patients (60%). Actuarial graft patency was 100%, 96%, and 56% after 2, 5, and 10 years and was lower in patients with diabetes (P=0.001). Deterioration of anterior wall motion was observed in 17 patients (34%) and was more frequent if anterior wall motion was preoperatively normal (P=0.002), irrespective of LAD graft patency.

CONCLUSION

Clinical status and long-term graft patency of grafts on endarterectomized LAD is considerable. However, patients with preoperatively normal anterior wall function are at increased risk for myocardial damage in the long-term.

[Myocardial perfusion scintigraphy in Germany. Results of the 2005 query and current status]

The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine (DGN), in cooperation with the working group Nuclear Cardiology of the German Cardiac Society (DGK), decided to conduct a national survey on myocardial perfusion scintigraphy (MPS).

METHOD

A questionnaire to evaluate MPS for the year 2005 was sent.

RESULTS

346 completed questionnaires had been returned (213 private practices, 99 hospitals and 33 university hospitals). MPS of 112 707 patients were reported with 110 747 stress and 95 878 rest studies. The majority (>75%) was performed with (99m)Tc-MIBI or tetrofosmin. (201)Tl stress-redistribution was used in 22 637 patients (20%). The types of stress were exercise in 78%, vasodilation with adenosine or dipyridamol in 21% and dobutamine in 1%. 99.97% of all MPS were SPECT studies. Gated SPECT was performed in 36% of the stress and in 32% of the rest studies. An attenuation correction was used in 21%. 29 institutions (8%) performed gated SPECT (stress and rest) and attenuation correction. 47% of all MPS were requested by ambulatory care cardiologists, 17% by internists, 12% by primary care physicians, 21% by hospital departments and 2% by others.

CONCLUSION

In Germany, MPS is predominantly performed with (99m)Tc-perfusion agents. The common type of stress is ergometry. Gated SPECT and attenuation correction do not yet represent standards of MPS practice in Germany, which indicates some potential of optimization.

Rotational atherectomy for the treatment of in-stent restenosis

Restenosis after coronary stent implantation remains the major limitation of this treatment modality. At present, re-dilatation is considered the therapeutic option of choice for focal lesions, however, long restenotic lesions (>10 mm) do not respond favourably. Despite the emerging concept of intracoronary radiation, encouraging acute procedural results are also reported for different debulking techniques (Excimer laser angioplasty, directional coronary atherectomy, and rotational atherectomy, or rotablation). Rotablation has been studied most extensively with acute and long- term results published in a total of more than 850 patients. Experimental and first clinical data indicate favourable results for the rotablator as compared to balloon angioplasty alone for the treatment of in-stent restenosis. Data from the first 2 randomized clinical trials (ROSTER-, and ARTIST-trial) have now been published with conflicting results: The european multicenter ARTIST-trial including 300 patients could not prove a benefit for the rotablator as compared to re-dilatation in patients with diffuse stent restenosis. On the contrary, the monocenter ROSTER-trial, which has been presented as an abstract until today, suggests a clinical benefit of patients treated by the rotablator if they were studied with intracoronary ultrasound prior to randomization. Currently, rotablation for the treatment of restenosis cannot be considered as the first line treatment modality in patients with in-stent restenosis. As a result of unsatisfying angiographic and clinical long-term results by the use of a variety of treatment modalities in diffuse stent restenosis, prevention of this iatrogenic entity has become mandatory.

Development of a new biodegradable intravascular polymer stent with simultaneous incorporation of bioactive substances

OBJECTIVE

Due to the thrombogenicity and permanent implant nature of metallic stents, bioresorable synthetic polymers have been proposed for stents and local drug delivery systems. Bioresorbable polyesters like poly(D,L-lactide) demonstrated excellent biocompatibility in various tissues. This paper describes a novel method for the molding of these polymers. The specific CESP-process (Controlled Expansion of Saturated Polymers) is characterised by the use of the plasticizer carbon dioxide and allows the incorporation of bioactive substances at physiologic temperatures into the polymer bulk and the production of complex designed implants.

METHODS

The CESP-process is characterised by the exposure of an amorphous polymer to an inert gas at high pressure with a significant lower glass transition point. The plasticizing effect makes it possible to process polylactides at a temperature close to room temperature. The low process temperature constitutes a key advantage for thermally sensitive polymers and allows the incorporation of thermally sensitive pharmaceutical additives. To obtain some preliminary information on the biocompatibility, in vitro cell toxicity testing as well as drug release assessment was performed.

RESULTS

Different polymer sheets were produced using the CESP-process. Cytotoxicity was not observed in any molded polymer material. According to the mechanical and biocompatibility results Poly(D,L-lactide) (P-DL-LA) was investigated in the CESP-process. Finite element analysis was used to test the possible geometry of an adequate stent. A helical design was chosen and a stent-prototype was produced using the CESP-process. Peroxidase activity as an incorporated marker enzyme could be measured over 6 weeks. Different drug release profiles were obtained due to various pore sizes of the polymer.

CONCLUSIONS

The new CESP-process can be used to process biodegradable polymers and to mold different stent geometries without inducing cytotoxic effects to the material. Furthermore, this procedure permits the simultaneous incorporation of bioactive substances during the molding process. Drug release kinetics can be regulated by different pore sizes of the material.

99Tcm-methoxyisobutylisonitrile stress/rest SPECT in patients with constant complete left bundle branch block

Numerous studies have revealed frequent false positive septal findings of 201Tl stress imaging in patients with left bundle branch block (LBBB) even with angiographically excluded significant coronary artery disease (CAD). To scrutinize this phenomenon for stress/rest 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) was used to review 22 patients with constant LBBB. The findings were reversible septal defect in one patient, partially reversible septal defect in one patient and irreversible septal defects in eight patients. In four patients 99Tcm-MIBI scans were entirely normal. Thus, 12/22 (55%) patients revealed normal septal 99Tcm-MIBI uptake. Both patients with a stress-induced septal defect revealed a significant left anterior descending artery stenosis on coronary angiography. These preliminary results suggest, that 99Tcm-MIBI might be more specific and accurate than 201Tl in the evaluation of CAD in patients with LBBB because of apparently rare or absent false positive septal findings.

Successful treatment of massive pulmonary embolism by combined mechanical and thrombolytic therapy

In two patients with massive pulmonary embolism and cardiogenic shock requiring mechanical ventilation and prolonged external cardiac massage, occluded pulmonary arteries were recanalized by primary mechanical fragmentation of thrombi using a percutaneously inserted catheter followed by fibrinolytic therapy. The hemodynamic and respiratory parameters rapidly and greatly improved. Pulmonary angiography before discharge revealed normal results in both patients. No central neurological abnormalities were detected. It is concluded that patients with cardiogenic shock due to massive pulmonary embolism may benefit from immediate mechanical thrombus fragmentation followed by fibrinolysis when thrombolysis or surgical embolectomy are strictly contraindicated or not available.