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- Samano, Ninos, 1972-
(författare)
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No-Touch Saphenous Veins in Coronary Artery Bypass Grafting : Long-term Angiographic, Surgical, and Clinical Aspects
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ischemic heart disease is currently the leading cause of death globally. Coronary artery bypass grafting (CABG) is considered the best treatment for many patients and its success depends on the long-term patency of the conduits. Greater use of arterial grafts has been advocated because of their higher long-term patency compared to saphenous vein grafts (SVGs). Despite this, SVGs account for up to 80% of all grafts used in CABG. Consequently, the long-term patency of the saphenous vein (SV) is one of the most crucial challenges in cardiovascular surgery. The no-touch (NT) SV in CABG has shown a superior patency rate, slower progression of atherosclerosis, and better clinical outcome compared to conventional veins up to 8.5 years postoperatively. The aim of this thesis was to study the long-term angiographic, echocardiographic, and clinical aspects of CABG patients receiving either NT or conventional vein grafts and to investigate the health-related quality of life (HRQoL) in this patient group. Studies I-II report a randomized trial between NT and conventional veins where 74 patients were followed-up at a mean of 16 years postoperatively. Study III is a prospective cohort trial in which 97 patients with NT vein grafts anastomosed to the left anterior descending artery (LAD) were included and followed-up at a mean of 6 years postoperatively. Study IV included 257 patients in whom HRQoL and graft patency were studied during the same follow-up visit. Overall, NT vein grafts showed a higher patency compared to conventional veins at a mean of 16 years, 83% vs. 64% (p=0.03), which was similar to the patency of the left internal thoracic artery, 88%. The NT group had a better left ventricular ejection fraction compared to the conventional group, 57.9% vs. 49.4% (p=0.011). After a mean of 6 years, the patency rate of NT SVs to the LAD was 95.6% and to non-LAD targets, 93.9%. Graft patency was an independent predictor of HRQoL in CABG patients. These patients reported a function and wellbeing similar to that of the Swedish population and clearly higher health status than those in the same disease group in the general population.
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| 2. |
- Vidlund, Mårten, 1968-
(författare)
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Glutamate for metabolic intervention in coronary surgery : with special reference to the GLUTAMICS-trial
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Myocardial ischemia is a major cause of postoperative heart failure and adverse outcome in coronary artery bypass graft surgery (CABG). Conventional treatment of postoperative heart failure with inotropic drugs may aggravate underlying ischemic injury. Glutamate has been claimed to increase myocardial tolerance to ischemia and promote metabolic and hemodynamic recovery after ischemia. The aim of this work was to investigate if intravenous glutamate infusion given in association with CABG for acute coronary syndrome can reduce mortality and prevent or mitigate myocardial injury and postoperative heart failure. We also wanted to assess neurological safety issues, as a concern with the use of glutamate is that it may act as an excitotoxin under certain conditions.A metabolic strategy for perioperative care was assessed in an observational study on 104 consecutive patients with severe left ventricular dysfunction undergoing CABG. Based on encouraging clinical results, unsurpassed in the literature, the GLUTAMICS-trial was initiated. 861 patients undergoing CABG for acute coronary syndrome were randomly allocated to blinded intravenous infusion of L-glutamicacid solution or saline. The primary endpoint was a composite of postoperative mortality (≤30 days), perioperative myocardial infarction and left ventric ular heart failure in association with weaning from cardiopulmonary bypass. Secondary endpoints included neurological safety issues, degree of myocardial injury,postoperative hemodynamic state, use of circulatory support and cardiac mortality.The event rate was lower than anticipated and the primary endpoint did not differ significantly between the groups. Regarding secondary endpoints there were significant differences compatible with a beneficial effect of glutamate on post-ischemic myocardial recovery. The putative effect of glutamate infusion was seen in more ischemic patients (CCS class IV) and in patients with evident or anticipated LV-failure on weaning from CPB. No evidence for increased incidence of clinical or subclinical neurological injury was found. In conclusion, intravenous glutamate infusion is safe in the dosages employed and could provide a novel and important way of promoting myocardial recovery after ischemic injury.
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| 3. |
- Granfeldt, Hans, 1960-
(författare)
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The use of mechanical circulatory support and passive ventricular constraint in patients with acute and chronic heart failure
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many patients are diagnosed as having chronic heart failure (CHF) and apart from the fact that daily activities are impaired, they are great consumers of health care, and the prognosis is poor. The distinction between acute heart failure (AHF) and CHF may be difficult and is more a question of time rather than severity. The “gold standard” treatment for end‐stage heart failure is heart transplantation. Due to organ shortage this is reserved for selected patients only. Since the introduction of mechanical circulatory support (MCS) more and more patients with progressive CHF have been bridged‐to‐heart‐transplantation. There are MCS systems available for both short‐ and long‐term support. Newer concepts such as ventricular constraint to prevent ventricular remodelling are on the way. We have investigated short‐ (ImpellaTM) and long‐term (HeartMateTM I and II) MCS and ventricular constraint (CorCapTM CSD) as treatment concepts for all forms of heart failure, the aims being: bridge‐to‐decision, bridge‐to‐transplant and extended therapy, called “destination therapy” (DT).Methods and results: In Paper I, the use of HM‐ITM pulsatile MCS in bridge‐to‐transplantation patients in Sweden was retrospectively investigated regarding outcome and risk factors for mortality and morbidity. Fifty‐nine patients were treated between 1993 and 2002. The dominating diagnosis was dilated cardiomyopathy in 61%. Median support time was 99.5 days. 18.6% died before transplantation. Four patients needed RV assist due to right ventricular failure. Haemorrhage was an issue. Six patients (10%) suffered a cerebrovascular thromboembolic lesion. 15% developed driveline infection. 45% of the MCS patients were discharged home while on pump treatment. Massive blood transfusion was a predictor for mortality and morbidity, p<0.001.In Paper II the second generation long‐term MCS, the continuous axial flow pump HM‐IITM, was prospectively evaluated for mortality and morbidity. Eleven patients, from 2005 until 2008, were consecutively included at our institution. One patient received the pump for DT. The median pump time was 155 days. Survival to transplantation was 81.8%. Ten patients could be discharged home before transplantation after a median time of 65 days.Paper III investigated the Swedish experience and outcome of short‐term axial flow MCS, the ImpellaTM, in patients with AHF. Fifty patients were collected between 2003 and 2007 and divided into two groups: 1. Surgical group (n=33) with cardiogenic shock after cardiac surgery; and 2. Non‐surgical group (n=17), patients with AHF due to acute coronary syndromes with cardiogenic shock (53%) and myocarditis (29%). The 1‐year survival was 36% and 70%, respectively. 52% were reoperated because of bleeding. Predictors for survival at 30 days were preoperatively placed IABP (p=0.01), postoperatively cardiac output at 12 hours and Cardiac Power Output at 6 and 12 hours.In Paper IV we evaluated the use and long term outcome of ventricular constraint CorCapTM CSD. Since 2003, 26 consecutive patients with chronic progressive heart failure were operated with CSD via sternotomy (n=25) or left mini‐thoracotomy (n=1). Seven patients were operated with CorCapTM only. Nineteen patients had concomitant cardiac surgery. There were three early and three late deaths. The remaining cohort (n=18) was investigated in a cross‐sectional study regarding QoL with SF‐36. There was no difference in QoL measured with SF‐36 after a mean 3‐years follow up period, when compared to an age‐ and sex‐matched control group from the general population. The one‐year survival was 86%, and after three years 76%. Echocardiographic dimensions had improved significantly after three years.Conclusion: In our unit, a non‐transplanting medium‐sized cardiothoracic department, short‐ and long‐term MCS (ImpellaTM resp. HMTM) in patients with acute or chronic HF have been used with good results. The use of ventricular constraint early in the course of the disease is a good adjunct to other treatment options in progressive chronic HF patients.
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