Out-of-hospital cardiac arrest and percutaneous coronary intervention for ST-elevation myocardial infarction: long-term survival and neurological outcome.

BACKGROUND: Predictors of long-term outcome after ST-elevation myocardial infarction (STEMI) complicated by out-of-hospital cardiac arrest (OHCA) are incompletely understood, including the influence of successful coronary reperfusion. METHODS: We analysed clinical and procedural data as well as 1-year outcome of 72 consecutive patients who underwent primary coronary intervention (PCI) after witnessed OHCA and STEMI and compared the results with 695 patients with STEMI and PCI, but without OHCA. Neurological recovery after OHCA was assessed using the Cerebral Performance Category (CPC) scale. RESULTS: PCI was successful in 83.3% after OHCA vs. 84.3% in the non-OHCA group (p=0.87). One-year mortality was 34.7% vs. 9.5% (p<0.001). 58.3% of the OHCA-patients showed complete neurological recovery (CPC 1) or moderate neurological disability (CPC 2). Another 6.9% showed severe cerebral disability (CPC 3) or permanent vegetative status (CPC 4). Delay from collapse until start of Advanced Cardiopulmonary Life Support (ACLS) was shorter for survivors with CPC status ≤2 (median 1 min, range 0-11 min) compared to non-survivors or survivors with CPC status >2 (median 8 min, range 0-13 min), p<0.0001. Age-adjusted multivariate analysis identified 'unsuccessful PCI', 'vasopressors on admission' and 'start of ACLS after >6 min' as independent predictors of negative long-term outcome (death or CPC >2). CONCLUSIONS: Mortality is high in patients with STEMI complicated by OHCA - even though PCI was performed with the same success rate as in patients without OHCA. The majority of survivors had favourable neurological outcomes at 1 year, especially if advanced life support had been started within ≤6 min and PCI was successful.

Cytochrome rC552, formed during expression of the truncated, Thermus thermophilus cytochrome c552 gene in the cytoplasm of Escherichia coli, reacts spontaneously to form protein-bound 2-formyl-4-vinyl (Spirographis) heme.

Expression of the truncated (lacking an N-terminal signal sequence) structural gene of Thermus thermophilus cytochrome c(552) in the cytoplasm of Escherichia coli yields both dimeric (rC(557)) and monomeric (rC(552)) cytochrome c-like proteins [Keightley, J. A., et al. (1998) J. Biol. Chem. 273, 12006-12016], which form spontaneously without the involvement of cytochrome c maturation factors. Cytochrome rC(557) is comprised of a dimer and has been structurally characterized [McRee, D., et al. (2001) J. Biol. Chem. 276, 6537-6544]. Unexpectedly, the monomeric rC(552) transforms spontaneously to a cytochrome-like chromophore having, in its reduced state, the Q(oo) transition (alpha-band) at 572 nm (therefore called p572). The X-ray crystallographic structure of rC(552), at 1.41 A resolution, shows that the 2-vinyl group of heme ring I is converted to a [heme-CO-CH(2)-S-CH(2)-C(alpha)] conjugate with cysteine 11. Electron density maps obtained from isomorphous crystals of p572 at 1.61 A resolution reveal that the 2-vinyl group has been oxidized to a formyl group. This explains the lower energy of the Q(oo)() transition, the presence of a new, high-frequency band in the resonance Raman spectra at 1666 cm(-1) for oxidized and at 1646 cm(-1) for reduced samples, and the greatly altered, paramagnetically shifted (1)H NMR spectrum observed for this species. The overall process defines a novel mechanism for oxidation of the 2-vinyl group to a 2-formyl group and adds to the surprising array of chemical reactions that occur in the interaction of heme with the CXXCH sequence motif in apocytochromes c.

Synthesis and Structure of a Zirconium Dinitrogen Complex with a Side-On Bridging N(2) Unit.

Reduction of Zr(O-2,6-Me(2)C(6)H(3))Cl(2)[N(SiMe(2)CH(2)PPr(i)(2))(2)] with sodium amalgam under dinitrogen yields the dinuclear zirconium dinitrogen complex {[(Pr(i)(2)PCH(2)SiMe(2))(2)N]Zr(O-2,6-Me(2)C(6)H(3))}(2)(&mgr;-eta(2):eta(2)-N(2)). Solid state structural analysis shows that the dinitrogen unit is bound in a side-on mode of coordination with the N-N bond distance at 1.528(7) Å; resonance Raman spectra show a band at 751 cm(-)(1) for nu(N-N), which is consistent with this very long bond. In addition, the N(2) ligand is hinged slightly so that the Zr(2)(&mgr;-eta(2):eta(2)-N(2)) core adopts a flattened butterfly shape rather than a completely planar core as found in other related systems. Other Zr(IV) precursors of the general formula ZrCl(2)X[N(SiMe(2)CH(2)PPr(i)(2))(2)] (X = OBu(t), OCHPh(2), NPh(2)) either decompose upon reduction under N(2) or produce mixtures of products.