Microcirculatory perfusion is preserved during off-pump but not on-pump cardiac surgery.

OBJECTIVE: This study investigated the perioperative course of microcirculatory perfusion in off-pump compared with on-pump surgery. Additionally, the impact of changes in systemic hemodynamics, hematocrit, and body temperature was studied. DESIGN: Prospective, nonrandomized, observational study. SETTING: Tertiary university hospital. PARTICIPANTS: Patients undergoing coronary artery bypass grafting with (n = 13) or without (n = 13) use of cardiopulmonary bypass. INTERVENTIONS: Microcirculatory measurements were obtained at 5 time points ranging from induction of anesthesia to ICU admission. MEASUREMENTS AND MAIN RESULTS: Microcirculatory recordings were performed with sublingual sidestream dark field imaging. Despite a comparable reduction in intraoperative blood pressure between groups, the perfused vessel density decreased more than 20% after onset of extracorporeal circulation but remained stable in the off-pump group. The reduction in microvascular perfusion in the on-pump group was further paralleled by decreased hematocrit and temperature. Although postbypass hematocrit levels and body temperature were restored to similar levels as in the off-pump group, the median microvascular flow index remained reduced after bypass (2.4 [2.3-2.7]) compared with baseline (2.8 [2.7-2.9]; p = 0.021). CONCLUSIONS: Microcirculatory perfusion remained unaltered throughout off-pump surgery. In contrast, microvascular perfusion declined after initiation of cardiopulmonary bypass and did not recover in the early postoperative phase.

EXpansion of stents after intravascular lithoTripsy versus conventional predilatation in CALCified coronary arteries.

BACKGROUND: Coronary artery calcification is a strong predictor for procedural failure and is independently associated with adverse events after percutaneous coronary intervention (PCI). An important contributor to the impaired outcome is the inability to achieve optimal results due to stent underexpansion or stent deformation/fracture. Intravascular lithotripsy (IVL) has emerged as an alternative technique to change the integrity of calcified plaques. AIMS: Our aim was to investigate if pre-treatment with IVL in severely calcified lesions increases stent expansion, assessed by optical coherence tomography (OCT), when compared to predilatation with conventional and/or specialty balloon strategy. METHODS: EXIT-CALC was a prospective, single-centre, randomised controlled study. Patients with an indication for PCI and severe calcification of the target lesion were allocated to predilatation with conventional angioplasty balloons or pre-treatment with IVL, followed by drug-eluting stenting and mandatory postdilatation. Primary endpoint was stent expansion assessed by OCT. Secondary endpoints were the occurrence of peri-procedural events and major adverse cardiac events (MACE) in hospital and during follow-up. RESULTS: A total of 40 patients were included. The minimal stent expansion in the IVL-group (n = 19) was 83.9 ± 10.3% and 82.2 ± 11.5% in the conventional group (n = 21) (p = 0.630). Minimal stent area was 6.6 ± 1.5 mm2 and 6.2 ± 1.8 mm2, respectively (p = 0.406). No peri-procedural, in-hospital and 30-day follow-up MACE were reported. CONCLUSIONS: In severely calcified coronary lesions we found no significant difference in stent expansion measured by OCT when comparing IVL, as plaque modification, with conventional and/or specialty angioplasty balloons.

Case report of an acute myocardial infarction after high-dose recreational nitrous oxide use: a consequence of hyperhomocysteinaemia?

BACKGROUND: Nitrous oxide (N2O, laughing gas) is increasingly used as a recreational drug and is presumed relatively safe and innocent. It is often being used in combination with other substances, such as cannabis. CASE SUMMARY: A young adult attended the emergency room because of chest pain after recreational use of very high-dose nitrous oxide in combination with cannabis. Electrocardiography demonstrated ST-elevation in the anterior leads. Coronary angiography showed thrombus in the proximal and thrombotic occlusion of the distal left anterior descending coronary artery for which primary percutaneous coronary intervention was attempted. Thrombus aspiration was unsuccessful and the patient was further treated with a glycoprotein IIb/IIIa in addition to dual platelet therapy. Blood results showed low vitamin B12 and folic acid status with concomitant hyperhomocysteinaemia, a known cause of hypercoagulation. Transthoracic echocardiogram showed a moderately reduced left ventricular ejection fraction (LVEF). Three months later, an improvement in LVEF and no recurrent angina or symptoms of heart failure were noticed. DISCUSSION: We report a case of acute myocardial infarction secondary to very high-dose nitrous oxide abuse in combination with cannabis and possible hypoxia. We propose that severe hyperhomocysteinaemia secondary to nitrous oxide-induced vitamin B12 deficiency together with the vasoconstrictive effects of cannabis might pose a seriously increased risk for intracoronary, among others, thrombus formation. In conclusion, we contest the safety and innocence of recreational nitrous oxide (ab)use, notably in the context of other factors increasing the risk of coagulation.

[Thromboembolisms due to recreational use of nitrous oxide]. / Trombo-embolieën door recreatief lachgasgebruik.

Nitrous oxide (N2O) is increasingly used as a recreational drug, and is presumed relatively safe and innocent. The risks for neurological complications are often known, however the risks of serious thromboembolic events are not. We describe three cases of acute thromboembolic events resulting in serious cardiovascular complications after N2O abuse: one case of myocardial infarction that resulted in a reduced ejection fraction, one case of peripheral arterial occlusion that led to limb amputation and one case of pulmonary embolism that resulted in hemodynamic instability requiring extracorporeal membrane oxygenation (ECMO) and surgical removal. All patients were young adults with a low cardiovascular risk profile. N2O inactivates vitamin B12, leading to vitamin B12 deficiency and subsequent to hyperhomocysteinemia, which is associated with the formation of fibrinolysis-resistant blood thrombi. In conclusion, we contest the safety and innocence of recreational N2O (ab)use. Our three cases illustrate that, next to previously described neurological complications, the use of nitrous oxide is associated with thromboembolic cardiovascular complications, presumably mediated by hyperhomocysteinemia.

The Alkmaar CTO Registry: A Retrospective Cohort Evaluating the Introduction of a Dedicated CTO Program.

BACKGROUND: Percutaneous coronary interventions (PCI) of chronic total occlusions (CTO) are high risk procedures with low success rates compared to standard PCI. Recently the 'hybrid approach' method has been developed to increase success rate. In 2015 we set up a dedicated program to systematically treat CTOs by this hybrid approach. This retrospective, observational registry aims to report achieved results in a single PCI centre. METHODS AND RESULTS: We reviewed all CTO procedures between January 2012 and December 2017. Procedures performed by dedicated operators after December 2014 were assigned to the hybrid cohort, procedures done before this time or performed by a non-CTO operator were assigned to the non-hybrid cohort. Procedural techniques, difficulty of lesions, J-CTO scores, outcomes and complications were analysed. In total 505 procedures were included. Average J-CTO score was 1.9 ± 1.1, which was significantly higher in the hybrid cohort (2.1 ± 1.2 vs. 1.6 ± 1.1; p < 0.001). Overall procedural success rate was 75.4% with significantly higher success rates in the hybrid cohort (81.2% vs. 68.2%; p < 0.001). Combining both cohorts, overall success rate increased over the years (2012-2017 respectively 65.2%, 60.0%, 71.7%, 83.2%, 77.9% and 81.4%). Complication rate was higher in the hybrid cohort compared to the non-hybrid cohort (4.6% vs 0.4%, respectively; p = 0.026). CONCLUSION: By introducing a systematic CTO program, including use of the hybrid approach, we observed higher success rates of PCI CTO, despite increased complexity of the lesions (higher J-CTO score). The occurrence of MACE was in accordance with current literature. CONDENSED ABSTRACT: Our registry demonstrates that introduction of a dedicated CTO program increases success rates of CTO treatments despites increased lesions difficulty and with acceptable MACEs rates.