Jassim Al Suwaidi

Long-Term Follow-Up of Patients With Mild Coronary Artery Disease and Endothelial Dysfunction

BACKGROUNDnCoronary endothelial dysfunction is characterized by vasoconstrictive response to the endothelium-dependent vasodilator acetylcholine. Although endothelial dysfunction is considered an early phase of coronary atherosclerosis, there is a paucity of information regarding the outcome of these patients. Thus, this study was designed to evaluate the outcome of patients with mild coronary artery disease on the basis of their endothelial function.nnnMETHODS AND RESULTSnFollow-up was obtained in 157 patients with mildly diseased coronary arteries who had undergone coronary vascular reactivity evaluation by graded administration of intracoronary acetylcholine, adenosine, and nitroglycerin and intracoronary ultrasound at the time of diagnostic study. Patients were divided on the basis of their response to acetylcholine into 3 groups: group 1 (n=83), patients with normal endothelial function; group 2 (n=32), patients with mild endothelial dysfunction; and group 3 (n=42), patients with severe endothelial dysfunction. Over an average 28-month follow-up (range, 11 to 52 months), none of the patients from group 1 or 2 had cardiac events. However, 6 (14%) with severe endothelial dysfunction had 10 cardiac events (P<0.05 versus groups 1 and 2). Cardiac events included myocardial infarction, percutaneous or surgical coronary revascularization, and/or cardiac death.nnnCONCLUSIONSnSevere endothelial dysfunction in the absence of obstructive coronary artery disease is associated with increased cardiac events. This study supports the concept that coronary endothelial dysfunction may play a role in the progression of coronary atherosclerosis.

Immediate and long-term outcome of intracoronary stent implantation for true bifurcation lesions

OBJECTIVESnThe aim of this study was to evaluate the immediate and long-term outcome of intracoronary stent implantation for the treatment of coronary artery bifurcation lesions.nnnBACKGROUNDnBalloon angioplasty of true coronary bifurcation lesions is associated with a lower success and higher complication rate than most other lesion types.nnnMETHODSnWe treated 131 patients with bifurcation lesions with > or =1 stent. Patients were divided into two groups; Group (Gp) 1 included 77 patients treated with a stent in one branch and percutaneous transluminal coronary angioplasty (PTCA) (with or without atherectomy) in the side branch, and Gp 2 included 54 patients who underwent stent deployment in both branches. The Gp 2 patients were subsequently divided into two subgroups depending on the technique of stent deployment. The Gp 2a included 19 patients who underwent Y-stenting, and Gp 2b included 33 patients who underwent T-stenting.nnnRESULTSnThere were no significant differences between the groups in terms of age, gender, frequency of prior myocardial infarction (MI) or coronary artery bypass grafting (CABG), or vessels treated. Procedural success rates were excellent (89.5 to 97.4%). After one-year follow-up, no significant differences were seen in the frequency of major adverse events (death, MI, or repeat revascularization) between Gp 1 and Gp 2. Adverse cardiac events were higher with Y-stenting compared with T-stenting (86.3% vs. 30.4%, p = 0.004).nnnCONCLUSIONSnStenting of bifurcation lesions can be achieved with a high success rate. However, stenting of both branches offers no advantage over stenting one branch and performing balloon angioplasty of the other branch.

Obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries

OBJECTIVESnThis study evaluates the impact of obesity on coronary endothelial function in patients with normal or mild coronary artery disease.nnnBACKGROUNDnThe American Heart Association (AHA) has recently classified obesity as a modifiable risk factor for coronary heart disease.nnnMETHODSnA total of 397 consecutive patients with normal or mildly diseased coronary arteries at angiography underwent coronary vascular reactivity evaluation using intracoronary adenosine, acetylcholine and nitroglycerin. Patients were divided into three groups based on the body mass index (BMI): Group 1, patients with a BMI <25 (n = 117, normal weight); Group 2, patients with a BMI 25-30 (n = 149, overweight) and Group 3, patients with a BMI >30 (n = 131, obese).nnnRESULTSnThere were no significant differences among the groups in regard to other cardiovascular risk factors, except that overweight but not obese patients were significantly older than normal-weight patients (47 +/- 1 years in Group 1, 53 +/- 1 years in Group 2 and 50 +/- 1 years in Group 3, p < 0.001). The percent change of coronary blood flow to acetylcholine (%delta CBF Ach) was significantly lower in the obese patients than in the normal-weight group (85.2 +/- 12.0% in Group 1, 63.7 +/- 10.0% in Group 2 and 38.1 +/- 9.6% in Group 3, p = 0.009). By multivariate analysis, overweight (odds ratio, 1.55; 95% confidence interval, 1.2-2.0) and obesity (odds ratio, 2.41; 95% confidence interval, 1.5-4.0) status were independently associated with impaired coronary endothelial function.nnnCONCLUSIONSnThe study demonstrates that obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries.

Immediate and one-year outcome in patients with coronary bifurcation lesions in the modern era (NHLBI dynamic registry).

Balloon angioplasty of bifurcation lesions has been associated with lower success and higher complication rates than most other lesion types. The development of alternative strategies such as debulking and stenting, either alone or in combination, are currently used relatively often. The relative role of these newer approaches in improving acute or long-term outcome, however, remains uncertain. Of the total of 2,436 patients treated between July 1997 to February 1998 in the National Heart, Lung, and Blood Institute Dynamic Registry, there were 321 patients (group 1) with bifurcation lesions and 2,115 patients without any bifurcation lesions attempted (group 2). Treatment strategies in terms of major devices used were significantly different between the 2 groups (group 1 vs 2): balloon angioplasty alone (23.1% vs 26.5%), balloon angioplasty and rotational atherectomy (6.9% vs 4.4%), balloon angioplasty and stent (55.8% vs 59.9%), and balloon angioplasty, rotational atherectomy, and stent (10.3% vs 7%) with p <0.01. There were no significant differences between the groups in terms of age, gender, and frequency of prior myocardial infarction (MI) or coronary artery bypass graft surgery (CABG). Complete angiographic success was achieved in only 86% of bifurcation lesions versus 93.5% of nonbifurcation lesions (p <0.001). In-hospital complication rates were increased in patients with bifurcation lesions compared with the nonbifurcation group: MI, 3.7% versus 2.6%; CABG, 2.2% versus 1.1%; side branch occlusion, 7.3% versus 2.3% (p <0.001); and the composite of death, MI, and any CABG, 7.2% versus 5.0%. At 1-year follow-up, major adverse cardiac events were 25% higher in group 1 than in group 2 (32.1% vs 25.7%, p <0.05). We conclude that despite the widespread use of newer percutaneous devices, treatment of bifurcation lesions remains difficult and is associated with decreased success and increased complication rates compared with nonbifurcation lesions.

Attenuated coronary flow reserve and vascular remodeling in patients with hypertension and left ventricular hypertrophy

OBJECTIVESnThe purpose of this study was to evaluate the association between hypertension and left ventricular hypertrophy (LVH) with both coronary vascular remodeling and endothelial function.nnnBACKGROUNDnThe association between endothelial and nonendothelial coronary flow reserve with vascular remodeling in patients with hypertension and LVH is still unclear.nnnMETHODSnOne hundred and eleven patients with normal or mildly diseased coronary arteries at angiography underwent intravascular ultrasound examination of the left anterior descending coronary artery. Patients were divided into three groups: group 1: n = 13, hypertensive patients with LVH; group 2: n = 30, hypertensive patients without LVH; group 3: n = 68, normotensive patients. Vessel and lumen area and atherosclerotic plaque area were evaluated. Vascular reactivity was examined using intracoronary adenosine and acetylcholine.nnnRESULTSnVessel area in group 1 (with LVH) was significantly (p < 0.01) greater than that in group 2 (without LVH), whereas, vessel area in both groups 1 and 3 was similar (12.8 +/- 0.8 mm2, 10.7 +/- 0.4 mm2 and 11.5 +/- 0.3 mm2). Coronary blood flow at baseline for patients in group 1 (with LVH) was significantly greater than it was for patients in groups 2 and 3 (81.1 +/- 9.9 ml/min, 56.5 +/- 6.2 ml/min and 48.1 +/- 3.2 ml/min, both p < 0.05). In comparison with groups 2 and 3, the response to both acetylcholine and adenosine was significantly impaired in patients with LVH.nnnCONCLUSIONSnThe current study demonstrates that hypertension with LVH is associated with both coronary vascular remodeling and attenuated endothelial and nonendothelial coronary flow reserve.

Cholesterol-Lowering Treatment Is Associated With Improvement in Coronary Vascular Remodeling and Endothelial Function in Patients With Normal or Mildly Diseased Coronary Arteries

Coronary vascular remodeling and altered endothelial function have been described in the early stages of native atherosclerosis. The purpose of this study was to evaluate the association between cholesterol-lowering therapy and coronary vascular remodeling and endothelial function in patients with normal or mildly diseases coronary arteries. Patients (N=101) with normal or mildly diseased coronary arteries by coronary angiography underwent intravascular ultrasound examination of the left anterior descending coronary artery. Vessel and lumen area, atherosclerotic plaque area, and plaque morphology were evaluated. Vascular reactivity was examined with the use of intracoronary adenosine, acetylcholine, and nitroglycerin. Patients were divided into 3 groups based on the total cholesterol levels: group 1 (n=25), patients with a history of hypercholesterolemia adequately treated (total cholesterol <240 mg/dL); group 2 (n=26), patients with hypercholesterolemia not adequately controlled (total cholesterol >/=240 mg/dL); and group 3 (n=50), patients without hypercholesterolemia. Vessel area and lumen area were significantly greater in groups 1 and 3 than in group 2 (for respective values in groups 1, 2, and 3: vessel area 11.9+/-0.5, 10.6+/-0.4, and 11.8+/-0.4 mm(2), both P<0.05; lumen area 8.3+/-0.4, 6.9+/-0.3, and 8.9+/-0.3 mm(2), both P<0.01). However, plaque areas in groups 1 and 2 were similar. Furthermore, acetylcholine-induced percent increases in coronary blood flow were significantly greater in groups 1 and 3 than in group 2 (for respective values in groups 1, 2, and 3: 70.5+/-20.1%, 22.8+/-13.7%, and 68.6+/-14.8%, both P<0. 05). Cholesterol-lowering treatment is associated with an improvement in coronary lumen area that results not from a decrease in plaque area but from an increase in vessel area, reflecting vascular remodeling. Additionally, this adaptive process may occur in association with an improvement of endothelium-dependent vasodilation of the resistance coronary artery.

Association between obesity and coronary atherosclerosis and vascular remodeling.

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Measuring maximal percent area stenosis poststent placement with intracoronary Doppler and the continuity equation and correlation with intracoronary ultrasound and angiography

Quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS) are methods for anatomic assessment of stent deployment. Intracoronary Doppler is primarily a method for the physiologic assessment of coronary stenoses. It correlates well with traditional noninvasive measurements of lesion significance. Intracoronary Doppler was used for the anatomic assessment of de novo coronary artery stenosis with variable success; however, its use for anatomic assessment of adequate stent deployment is unavailable. A rapid, automated software program was developed based on a modified continuity equation to calculate the maximal in-stent percent area stenosis by comparing the maximal in-stent velocity to an average reference velocity (proximal and distal). This study was designed to compare the Doppler method of an anatomic assessment with QCA and ICUS in 15 patients. Physiologic success of stent deployment was determined by the distal coronary flow reserve to 24 to 36 microg of intracoronary adenosine. Following successful stent deployment, distal coronary flow reserve increased significantly from a baseline of 1.6 +/- 0.5 to 2.9 +/- 1.1. There was a significant correlation between the maximal in-stent percent area stenosis as measured by Doppler and both QCA (r = 0.78, p <0.01) and ICUS (r = 0.84, p <0.01). This study demonstrates that maximal in-stent percent area stenosis can be measured by intracoronary Doppler and a novel software program. The intracoronary Doppler guidewire method can assess the adequacy of stent deployment using both anatomic and physiologic principles and may supplement other quantitative methodologies.

Comparison of immediate and one-year outcome after coronary angioplasty of narrowing <3 mm with those ≥3 mm (the National Heart, Lung, and Blood Institute Dynamic Registry)

Balloon angioplasty of small coronary artery lesions has been associated with lower success and higher complication rates than large coronary artery lesions. This study evaluates the in-hospital and 1-year outcome of the treatment of small coronary artery lesions in the modern era of interventional cardiology and compares it with the outcome of treating large coronary artery lesions. Of 1,658 patients with a single lesion treated from July 1997 to February 1998 in the National Heart, Lung, and Blood Institute (NHLBI) Dynamic Registry, there were 587 patients with small coronary artery lesions (<3 mm) and 1,071 patients with large coronary artery lesions (> or =3 mm). Success, in-hospital, and 1-year outcomes between both groups were compared. Patients with lesions in small coronary arteries were more often women, insulin-treated diabetics, and had undergone more prior coronary bypass graft surgery. Conventional angioplasty alone was performed more often and angioplasty with stents was performed less often in the small coronary artery than in the large coronary artery group. Angiographic success was slightly lower in the small coronary artery group (94.2% vs 96.9%, p <0.05). Periprocedural and in-hospital complication rates were similar in both groups. Likewise, at 1-year follow-up, major adverse cardiac events including death, myocardial infarction, and coronary artery bypass graft surgery were relatively low and comparable between the 2 groups, although patients with small coronary arteries were more likely to undergo repeat revascularization (17.4% vs 13.6%, p <0.05). Treatment of lesions in small coronary arteries in the modern era is associated with high success and low complication rates, comparable to the treatment of large coronary artery lesions, although the incidence of repeat revascularization was significantly greater at follow-up even if stents were used.

Optimizing the Use of Abciximab and Intracoronary Stents in Patients with Acute ST Elevation Myocardial Infarction

Acute ST elevation myocardial infarction (Stemi) is a cause of significant morbidity and mortality in patients with coronary artery disease. Reperfusion therapy, either with thrombolytic agents or primary percutaneous coronary intervention (PCI), is the mainstay of therapy. Worldwide, systemic thrombolysis is the more commonly utilized reperfusion strategy, although an increasing number undergo primary PCI. PCI techniques and adjuvant therapies are evolving. Stents appear to be more useful than thrombolytic therapy or PTCA in acute AMI, especially in decreasing the need for subsequent target lesion revascularization.In patients with Stemi, administration of abciximab with Stent placement decreased the primary endpoint [composite of major adverse cardiac events (death, reinfarction, urgent TVR)] by over 50% at 30 days in the Abciximab before Direct angioplasty and stenting in acute Myocardial Infarction Regarding Acute and Longterm follow-up (Admiral) trial, and the benefit appeared to be maintained at 6 months. Despite these promising results, administration of abciximab with a stent did not afford greater benefit over stent alone in the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (Cadillac) trial. The apparent lack of benefit with abciximab in the Cadillac trial may be explained by the fact that this trial was not powered to detect differences in mortality and enrolled patients were selected after angiography, and were thus at lower risk. The adjuvant therapies of intracoronary Stents and abciximab are becoming the standard of care, based on multiple studies. Stent placement during Stemi decreases the risk of restenosis and TVR. Treatment with abciximab may reduce the risk of acute adverse events in the short term.