International Journal of Cardiology

International Journal of Cardiology | Vol. 1, No. 12, December 2010 | pp. 89–96

DOI: 10.46882/2010/IJC/000021

Original Research Article

Therapeutic Hypothermia After Out-of-Hospital Cardiac Arrest: Impact of Early vs. Delayed Initiation on Neurological Outcomes

Lucas Meyer¹, Stefan Kaufmann¹, Dieter Weber²

¹Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria

²Department of Cardiology, University Hospital Zurich, Zurich, Switzerland

Abstract:
Therapeutic hypothermia (TH) improves survival and neurological recovery in patients resuscitated from out-of-hospital cardiac arrest (OHCA). However, the optimal timing for initiating cooling remains controversial. This study evaluated whether early pre-hospital initiation of TH improves neurological outcomes compared with delayed in-hospital initiation. We conducted a prospective cohort study of 240 comatose adult patients resuscitated from OHCA with an initial shockable rhythm. Patients were divided into two groups: the early cooling group (n = 112), where cold intravenous saline (4°C) was initiated in the pre-hospital setting by emergency medical services, and the delayed cooling group (n = 128), where cooling was initiated exclusively after intensive care unit (ICU) admission. The primary endpoint was a favorable neurological outcome at 6 months, defined as a Cerebral Performance Category (CPC) score of 1 or 2. The target temperature of 33°C was reached significantly faster in the early cooling group than in the delayed group (185 ± 42 minutes vs. 248 ± 55 minutes from resuscitation, p < 0.001). At 6 months, 54.5% of patients in the early cooling group achieved a favorable neurological outcome compared with 41.4% in the delayed cooling group (p = 0.04). Multivariable logistic regression confirmed that early cooling initiation was an independent predictor of good neurological recovery (odds ratio: 1.68, 95% CI: 1.02–2.76, p = 0.03). Rates of rearrest, severe infection, and bleeding did not differ significantly between the cohorts. Pre-hospital initiation of therapeutic hypothermia safely reduces the time to target temperature and significantly improves 6-month neurological outcomes in comatose survivors of OHCA.

Keywords: Therapeutic hypothermia, Out-of-hospital cardiac arrest, Neurological outcome, Resuscitation, Pre-hospital care

Received: September 01, 2010; Revised: October 14, 2010; Accepted: November 05, 2010; Published: December 15, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 12, pp. 89–96, DOI: 10.46882/2010/IJC/000021

International Journal of Cardiology | Vol. 1, No. 11, November 2010 | pp. 81–88

DOI: 10.46882/2010/IJC/000020

Original Research Article

Long-Term Prognostic Value of Exercise Stress Echocardiography in Patients with Asymptomatic Severe Aortic Regurgitation

Sven Lindstrom¹, Ingrid Johansson¹, Anders Nielsen²

¹Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden

²Department of Clinical Physiology, Aarhus University Hospital, Aarhus, Denmark

Abstract:
Managing asymptomatic patients with severe aortic regurgitation (AR) and preserved left ventricular (LV) ejection fraction is challenging. Exercise stress echocardiography may unmask latent LV myocardial dysfunction and help time surgical interventions. This study investigated the long-term prognostic value of exercise echocardiography parameters in asymptomatic severe AR. We prospectively followed 120 asymptomatic patients with severe AR and resting LVEF greater than 50%. All patients underwent symptom-limited treadmill exercise echocardiography at baseline. The development of an exercise-induced decrease or lack of increase in LVEF (defined as an change in LVEF less than 5%), along with limited contractile reserve, was evaluated. The primary clinical endpoint was a composite of the development of cardiac symptoms, new resting LV dysfunction (LVEF less than 50%), or cardiac mortality. Over a median follow-up period of 5.4 years, 42 patients (35.0%) reached the primary endpoint and underwent aortic valve surgery. A lack of contractile reserve during exercise (delta LVEF less than 5%) was observed in 38 patients (31.7%) at baseline. Multivariable Cox analysis demonstrated that an exercise-induced change in LVEF less than 5% was strongly and independently associated with the primary endpoint (hazard ratio: 2.85, 95% CI: 1.64–4.95, p < 0.001). Pre-exercise global longitudinal strain was also predictive. Exercise stress echocardiography provides substantial prognostic benefit in asymptomatic severe aortic regurgitation, showing that a lack of contractile reserve during exertion strongly predicts future clinical symptom development or explicit myocardial failure.

Keywords: Aortic regurgitation, Exercise stress echocardiography, Contractile reserve, Left ventricular function, Prognosis, Aortic valve surgery

Received: August 04, 2010; Revised: September 19, 2010; Accepted: October 12, 2010; Published: November 18, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 11, pp. 81–88, DOI: 10.46882/2010/IJC/000020

International Journal of Cardiology | Vol. 1, No. 4, April 2010 | pp. 25–32

DOI: 10.46882/2010/IJC/000013

Original Research Article

Impact of Diabetes Mellitus on Long-Term Outcomes Following Percutaneous Coronary Intervention with Drug-Eluting Stents

Kenji Tanaka¹, Aisha Al-Mansoori², Robert J. Gallagher³

¹Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan

²Cardiology Department, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates

³Cardiovascular Division, King's College London, London, United Kingdom

Abstract:
Diabetes mellitus (DM) significantly accelerates atherogenesis and worsens clinical outcomes after percutaneous coronary intervention (PCI). This study aimed to evaluate the 5-year clinical outcomes of diabetic patients undergoing PCI with first-generation drug-eluting stents (DES) compared to non-diabetic individuals in a real-world registry. We analyzed data from 1,250 consecutive patients (412 with DM, 838 without DM) who underwent successful DES implantation between 2004 and 2005. The primary endpoint was the 5-year rate of major adverse cardiac events (MACE), defined as a composite of all-cause death, non-fatal myocardial infarction (MI), and target lesion revascularization (TLR). At 5 years, the cumulative incidence of MACE was significantly higher in diabetic patients than in non-diabetic patients (26.5% vs. 15.8%, p < 0.001). This difference was driven by higher rates of both TLR (14.1% vs. 8.2%, p < 0.01) and all-cause mortality (9.7% vs. 5.4%, p = 0.02). Insulin-dependent diabetic patients (n = 134) experienced the highest MACE rate at 34.3%. Multivariable Cox regression analysis identified insulin-treated DM as an independent predictor of 5-year MACE (hazard ratio: 2.12, 95% CI: 1.54–2.92, p < 0.001). Stent thrombosis rates did not differ significantly between the overall diabetic and non-diabetic cohorts (2.4% vs. 1.8%, p = 0.45). Despite the use of drug-eluting stents, patients with diabetes mellitus, particularly those requiring insulin therapy, continue to exhibit substantially higher risks of long-term MACE and target lesion revascularization compared to non-diabetic individuals.

Keywords: Diabetes mellitus, Percutaneous coronary intervention, Drug-eluting stents, Long-term outcomes, Target lesion revascularization

Received: January 08, 2010; Revised: February 22, 2010; Accepted: March 12, 2010; Published: April 18, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 4, pp. 25–32, DOI: 10.46882/2010/IJC/000013

International Journal of Cardiology | Vol. 1, No. 5, May 2010 | pp. 33–40

DOI: 10.46882/2010/IJC/000014

Original Research Article

Transcatheter Aortic Valve Implantation versus Surgical Aortic Valve Replacement in High-Risk Elderly Patients: A Single-Center Experience

Jean-Pierre Dubois¹, Lucia Rossi², Pierre Vigneron¹

¹Department of Interventional Cardiology, Hôpital Européen Georges-Pompidou, Paris, France

²Department of Cardiac Surgery, University of Milan, Milan, Italy

Abstract:
Transcatheter aortic valve implantation (TAVI) has emerged as an alternative therapy to surgical aortic valve replacement (SAVR) for severe symptomatic aortic stenosis in patients at high operative risk. This study compared the short- and mid-term clinical outcomes of elderly, high-risk patients treated with either TAVI or SAVR at our institution. We retrospectively evaluated 180 consecutive patients aged 80 years or older with severe aortic stenosis and a Logistic EuroSCORE greater than or equal to 15% who underwent TAVI (n = 90) or SAVR (n = 90) between 2007 and 2009. The primary baseline mean Logistic EuroSCORE was comparable between groups (TAVI: 22.4% ± 5.3% vs. SAVR: 21.8% ± 4.9%, p = 0.42). At 30 days post-procedure, all-cause mortality was 6.7% in the TAVI group and 8.9% in the SAVR group (p = 0.58). The incidence of major vascular complications (11.1% vs. 2.2%, p = 0.02) and new permanent pacemaker implantation (15.6% vs. 4.4%, p = 0.01) was significantly higher in the TAVI group. Conversely, severe bleeding requiring blood transfusions (20.0% vs. 42.2%, p = 0.001) and acute kidney injury (4.4% vs. 13.3%, p = 0.04) were more frequent after SAVR. At 1-year follow-up, survival rates were similar between TAVI and SAVR (81.1% vs. 78.9%, log-rank p = 0.70). Both modalities demonstrated marked improvements in New York Heart Association functional class. In high-risk elderly patients, TAVI yields mid-term survival rates comparable to SAVR, with distinct periprocedural complication profiles.

Keywords: Aortic stenosis, Transcatheter aortic valve implantation, Surgical aortic valve replacement, High-risk patients, Mortality

Received: February 14, 2010; Revised: March 25, 2010; Accepted: April 10, 2010; Published: May 22, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 5, pp. 33–40, DOI: 10.46882/2010/IJC/000014

International Journal of Cardiology | Vol. 1, No. 8, August 2010 | pp. 57–64

DOI: 10.46882/2010/IJC/000017

Original Research Article

Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography compared with Invasive Coronary Angiography

Ahmed Al-Hassan¹, Fatima Al-Sayed¹, Youssef Benamour²

¹Department of Cardiology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia

²Division of Cardiovascular Radiology, Ibn Rochd University Hospital, Casablanca, Morocco

Abstract:
Multislice computed tomography coronary angiography (CTCA) has advanced rapidly as a non-invasive imaging modality for evaluating coronary artery disease (CAD). We evaluated the diagnostic performance of 64-slice CTCA in detecting hemodynamically significant coronary stenosis, using conventional invasive coronary angiography (ICA) as the gold standard reference. A prospective study was conducted on 150 symptomatic patients suspected of having stable CAD who were scheduled for ICA. All patients underwent 64-slice CTCA within 2 weeks prior to ICA. Coronary segments were assessed for the presence of significant stenosis, defined as a luminal diameter reduction greater than or equal to 50%. On a patient-based analysis, CTCA successfully identified significant CAD in 88 out of 94 patients confirmed by ICA. The patient-based sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 64-slice CTCA were 93.6% (95% CI: 86.6%–97.6%), 85.7% (95% CI: 73.8%–93.6%), 91.7% (95% CI: 84.2%–96.3%), and 88.9% (95% CI: 77.4%–95.8%), respectively. On a segment-based analysis (1,985 segments evaluable), the overall sensitivity and specificity were 86.4% and 95.8%. Diagnostic accuracy was lower in segments with severe calcification (Agatston calcium score greater than 400). No major adverse events were reported during CTCA scanning. Sixty-four-slice computed tomography coronary angiography provides high diagnostic accuracy and an exceptional negative predictive value for ruling out significant coronary artery disease in symptomatic patients, making it a reliable clinical triage tool prior to invasive angiography.

Keywords: Computed tomography coronary angiography, Invasive coronary angiography, Coronary artery disease, Sensitivity, Specificity, Diagnostic accuracy

Received: May 02, 2010; Revised: June 15, 2010; Accepted: July 04, 2010; Published: August 20, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 8, pp. 57–64, DOI: 10.46882/2010/IJC/000017

International Journal of Cardiology | Vol. 1, No. 9, September 2010 | pp. 65–72

DOI: 10.46882/2010/IJC/000018

Original Res

International Journal of Cardiology | Vol. 1, No. 7, July 2010 | pp. 49–56

DOI: 10.46882/2010/IJC/000016

Original Research Article

Cardioprotective Effects of Resveratrol in a Rat Model of Ischemia-Reperfusion Injury: Role of the SIRT1 Pathway

Li Wei¹, Zhang Min¹, Wang Wei²

¹State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing, China

²Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China

Abstract:
Myocardial ischemia-reperfusion (I/R) injury leads to irreversible tissue damage, cardiac dysfunction, and cardiomyocyte apoptosis. Resveratrol, a natural polyphenolic compound, possesses antioxidant and anti-apoptotic properties, but its underlying molecular mechanisms remain incompletely understood. This study investigated the protective effects of resveratrol against myocardial I/R injury in rats and explored the involvement of the Silent Information Regulator 1 (SIRT1) signaling pathway. Adult male Sprague-Dawley rats were randomized into four groups (n = 12 per group): Sham, I/R control, Resveratrol + I/R, and Resveratrol + EX527 (a SIRT1 inhibitor) + I/R. Ischemia was induced by occluding the left anterior descending coronary artery for 30 minutes, followed by 120 minutes of reperfusion. Resveratrol (20 mg/kg/day) was administered orally for 14 days prior to I/R. Pretreatment with resveratrol significantly reduced myocardial infarct size compared to the I/R control group (28.4% ± 3.5% vs. 44.6% ± 4.2%, p < 0.01). Resveratrol administration also preserved left ventricular developed pressure (LVDP) and attenuated the rise in serum creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) levels (p < 0.05). Furthermore, resveratrol up-regulated SIRT1 expression and down-regulated cleaved caspase-3 expression, leading to a marked reduction in TUNEL-positive apoptotic cardiomyocytes. Crucially, co-administration of the SIRT1 inhibitor EX527 abolished the infarct-limiting and anti-apoptotic benefits of resveratrol (infarct size: 41.2% ± 3.9%, p > 0.05 vs. I/R control). These findings indicate that resveratrol exerts potent cardioprotective actions against ischemia-reperfusion injury in rats by suppressing cardiomyocyte apoptosis via activation of the SIRT1 pathway.

Keywords: Ischemia-reperfusion injury, Resveratrol, SIRT1, Cardiomyocytes, Apoptosis, Infarct size

Received: April 10, 2010; Revised: May 20, 2010; Accepted: June 08, 2010; Published: July 25, 2010

Citation: International Journal of Cardiology, 2010, Vol. 1, No. 7, pp. 49–56, DOI: 10.46882/2010/IJC/000016