Exhibit 99.43 MBNA MASTER CREDIT CARD TRUST II SERIES 2000-B KEY PERFORMANCE FACTORS March 31, 2001 Expected B Maturity 2/18/03 Blended Coupon 5.3358% Excess Protection Level 3 Month Average 7.54% March, 2001 8.14% February, 2001 7.50% January, 2001 6.97% Cash Yield20.67% Investor Charge Offs 4.83% Base Rate 7.69% Over 30 Day Delinquency 4.90% Seller's Interest 7.37% Total Payment Rate14.60% Total Principal Balance$56,622,749,044.91 Investor Participation Amount$750,000,000.00 Seller Participation Amount$4,172,058,483.42